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Michiel W M Van Den Brekel - One of the best experts on this subject based on the ideXlab platform.
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tumor volume as a prognostic factor for local control and overall survival in advanced Larynx Cancer
Laryngoscope, 2016Co-Authors: Adriana J Timmermans, Josien De Bois, Charlotte A H Lange, Erik Van Werkhoven, Olga Hammingvrieze, F J M Hilgers, Michiel W M Van Den BrekelAbstract:Keywords: Head and neck Cancer; Larynx Cancer; organ preservation; total laryngectomy; imaging; tumor volume;prognosis; outcome Objectives/Hypothesis Tumor volume has been postulated to be an important prognostic factor for oncological outcome after radiotherapy or chemoradiotherapy. This postulate was retrospectively investigated in a consecutively treated cohort of T3-T4 Larynx Cancer patients. Study Design Retrospective cohort study. Methods For 166 patients with T3-T4 Larynx Cancer (1999-2008), pretreatment computed tomography and magnetic resonance imaging scans were available for tumor volume delineation. Patients were treated with radiotherapy, chemoradiotherapy, or total laryngectomy with postoperative radiotherapy. Both a dedicated head and neck radiologist and the first author determined all tumor volumes. Statistical analysis was by Kaplan-Meier plots and Cox proportional hazard models. Results Patients with T3 Larynx Cancer had significantly smaller tumor volumes than patients with T4 Larynx Cancer (median = 8.1 cm3 and 15.8 cm3, respectively; P < .0001). In the group treated with total laryngectomy and postoperative radiotherapy, no association was found between tumor volume and local or locoregional control or overall survival. In the group treated with radiotherapy, a nonsignificant trend was observed between local control and tumor volume. In the chemoradiotherapy group, however, a significant impact of tumor volume was found on local control (hazard ratio = 1.07; 95% confidence interval = 1.01-1.13; P = .028). Conclusions Tumor volume was not significantly associated with local control, locoregional control, or overall survival in the surgically treated group. In the group treated with radiotherapy, there was no statistically significant association, but a trend was observed between local control and tumor volume. Only in patients treated with concurrent chemoradiotherapy was a significant impact of tumor volume on local control found. Level of Evidence 4. Laryngoscope, 126:E60-E67, 2016
Christine G Gourin - One of the best experts on this subject based on the ideXlab platform.
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association of hospital volume with laryngectomy outcomes in patients with Larynx Cancer
Archives of Otolaryngology-head & Neck Surgery, 2019Co-Authors: Christine G Gourin, Matthew C Stewart, Kevin D Frick, Carole Fakhry, Karen T Pitman, David W Eisele, Matthew J AustinAbstract:Importance A volume-outcome association exists for Larynx Cancer surgery, but to date it has not been investigated for specific surgical procedures. Objectives To characterize the volume-outcome association specifically for laryngectomy surgery and to identify a minimum hospital volume threshold associated with improved outcomes. Design, Setting, and Participants In this cross-sectional study, the Nationwide Inpatient Sample was used to identify 45 156 patients who underwent laryngectomy procedures for a malignant laryngeal or hypopharyngeal neoplasm between January 2001 and December 2011. The analysis was performed in 2018. Hospital laryngectomy volume was modeled as a categorical variable. Main Outcomes and Measures Associations between hospital volume and in-hospital mortality, complications, length of hospitalization, and costs were examined using multivariate logistic regression analysis. Results Among 45 156 patients (mean age, 62.6 years; age range, 20-96 years; 80.2% male) at 5516 hospitals, higher-volume hospitals were more likely to be teaching hospitals in urban locations; were more likely to treat patients who had hypopharyngeal Cancer, were of white race/ethnicity, were admitted electively, had no comorbidity, and had private insurance; and were more likely to perform flap reconstruction or concurrent neck dissection. After controlling for all other variables, hospitals treating more than 6 cases per year were associated with lower odds of surgical and medical complications, with a greater reduction in the odds of complications with increasing hospital volume. High-volume hospitals in the top-volume quintile (>28 cases per year) were associated with decreased odds of in-hospital mortality (odds ratio, 0.45; 95% CI, 0.23-0.88), postoperative surgical complications (odds ratio, 0.63; 95% CI, 0.50-0.79), and acute medical complications (odds ratio, 0.63; 95% CI, 0.48-0.81). A statistically meaningful negative association was observed between very high-volume hospital care and the mean incremental length of hospitalization (−3.7 days; 95% CI, −4.9 to −2.4 days) and hospital-related costs (−$4777; 95% CI, −$9463 to −$900). Conclusions and Relevance Laryngectomy outcomes appear to be associated with hospital volume, with reduced morbidity associated with a minimum hospital volume threshold and with reduced mortality, morbidity, length of hospitalization, and costs associated with higher hospital volume. These data support the concept of centralization of complex care at centers able to meet minimum volume thresholds to improve patient outcomes.
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treatment short term outcomes and costs associated with Larynx Cancer care in commercially insured patients
Laryngoscope, 2018Co-Authors: Andrew T Day, Kevin D Frick, David W Eisele, Hsien Yen Chang, Harry Quon, Hyunseok Kang, A P Kiess, Christine G GourinAbstract:Objectives/Hypothesis To examine associations between treatment, complications, and costs in patients with laryngeal Cancer. Study Design Retrospective cross-sectional analysis of MarketScan Commercial Claim and Encounters data. Methods We evaluated 10,969 patients diagnosed with laryngeal Cancer from 2010 to 2012 using cross-tabulations and multivariate regression. Results Chemoradiation was significantly associated with supraglottic tumors (relative risk ratio [RRR] = 5.9 [4.4–7.8]), pretreatment gastrostomy (RRR = 4.0 [2.7–6.1]), and alcohol abuse (RRR = 0.5 [0.3–0.9]). Treatment-related complications occurred in 23% of patients, with medical complications in 22% and surgical complications in 7%. Chemoradiation (odds ratio [OR] = 3.7 [2.6–5.2]), major surgical procedures (OR = 4.9 [3.5–6.8]), reconstruction (OR = 7.7 (4.1–14.7)], and advanced comorbidity (OR = 9.7 [5.7–16.5] were associated with acute complications. Recurrent/persistent disease occurred in 23% of patients and was associated with high-volume care (OR = 1.4 [1.1–1.8]). Salvage surgery was performed in 46% of patients with recurrent/persistent disease and was less likely for supraglottic disease (OR = 0.5 [0.4–0.8]) and after chemoradiation (OR = 0.4 [0.2–0.6]). Initial treatment and 1-year overall costs for chemoradiation were higher than all other treatment categories, after controlling for all other variables including complications and salvage. High-volume care was associated with significantly lower costs of care for surgical patients but was not associated with differences in costs of care for nonoperative treatment. Conclusions In commercially insured patients <65 years old with laryngeal Cancer, chemoradiation was associated with increased costs, an increased likelihood of treatment-related medical complications, and a reduced likelihood of surgical salvage. Higher-volume surgical care was associated with lower initial treatment and 1-year costs of care. These data have implications for discussions of value and quality in an era of healthcare reform. Level of Evidence 2c Laryngoscope, 2017
Ari Hirvonen - One of the best experts on this subject based on the ideXlab platform.
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dna repair gene xrcc2 and xrcc3 polymorphisms and susceptibility to Cancers of the upper aerodigestive tract
International Journal of Cancer, 2004Co-Authors: Jarno Tuimala, Alain Sarasin, Simone Benhamou, Christine Bouchardy, Pierre Dayer, Ari HirvonenAbstract:Cigarette smoke can generate reactive oxygen species, which are capable of inducing double-strand breaks (DSBs) in DNA. Polymorphisms in XRCC2 and XRCC3 genes, involved in DSBs repair pathways, may alter an individual's susceptibility to smoking-related Cancers. We investigated the effect of XRCC2 Arg188His and XRCC3 Thr241Met polymorphisms in Cancer proneness in 121 oral/pharynx Cancer cases, 129 Larynx Cancer cases and 172 nonCancer controls, all Caucasian smokers. The XRCC2 His-allele was associated with a significantly increased risk of pharyngeal Cancer (OR=2.9, 95% CI: 1.3–6.2). No significant associations were observed between the XRCC3 Thr241Met polymorphism and overall risk of developing UADT Cancers. However, quite opposite to the expectations, a reduced risk of supraglottic Cancer was found for carriers of the XRCC3 Met variant allele (OR=0.3, 95% CI: 0.2–0.7). These findings provide evidence for the view that polymorphisms in DNA repair genes may modify individual susceptibility to smoking-related Cancers. © 2004 Wiley-Liss, Inc.
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Larynx Cancer risk in relation to glutathione s transferase m1 and t1 genotypes and tobacco smoking
Cancer Epidemiology Biomarkers & Prevention, 1998Co-Authors: Nadejda Jourenkova, Simone Benhamou, Christine Bouchardy, Pierre Dayer, M Reinikainen, Ari HirvonenAbstract:Glutathione S-transferase (GST) isoenzymes are involved in the detoxification of several tobacco smoke-derived carcinogens. It is thus conceivable that deficiency in GST activity due to homozygous deletion of the GSTM1 and GSTT1 genes (the null genotypes) may modulate susceptibility to smoking-induced Cancers. The effects of the GSTM1 and GSTT1 null genotypes on laryngeal Cancer risk were evaluated using peripheral blood DNA from 129 Larynx Cancer patients and 172 nonCancer controls, all of whom were regular smokers. Increased Larynx Cancer risk was related to the GSTM1 null genotype [odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.0-2.8]. The OR associated with the GSTT1 null genotype was increased, although not significantly (OR = 1.4, 95% CI = 0.7-2.9). Individuals with concurrent lack of GSTM1 and GSTT1 genes had a doubled, although not significant, risk for Larynx Cancer when compared with those having at least one of these genes (OR = 2.0, 95% CI = 0.8-5.2) and had almost a 3-fold risk (OR = 2.7, 95% CI = 1.0-7.4) when compared with those with both genes. Moreover, a significant interaction between the GSTM1 genotype and levels of tobacco consumption (P < 0.05) was found; the GSTM1 null genotype was associated with an increased risk of Larynx Cancer among smokers of 20 g/day or less (OR = 2.9, 95% CI = 1.3-6.3) but not among heavier smokers (OR = 1.0; 95% CI = 0.5-2.0). In contrast, the GSTT1 null genotype posed an increased, although not significant, risk among long-term smokers (OR = 2.3, 95% CI = 0.9-5.4).
Valentina Hodorenko - One of the best experts on this subject based on the ideXlab platform.
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The use of TiNi-based endografts in Larynx Cancer patients
'International Journal of Cancer Therapy and Oncology', 2015Co-Authors: Denis Kulbakin, Marat Muhamedov, Timofey Chekalkin, Ji-hoon Kang, Georgiy Choynzonov, Valentina Hodorenko, Victor GuntherAbstract:Purpose: Laryngeal Cancer constitutes 26-30% of all head and neck malignant tumors. It is remarkably common in men and it is primarily distributed between ages 40 and 70 years old, but the frequency rate is the highest between ages 50 and 60. Well-known etiologic factors of laryngeal Cancer include smoking, alcohol, human papilloma virus and radiation. It has been reported that the occurrence rate is up to 20 times higher in smokers compared to non-smokers, but the exact pathogenesis of the disease is still unknown.Despite an increasing role of non-adjuvant radiotherapy and/or chemotherapy in treatment of Larynx Cancer, the surgical technique is still a basic one both in combined treatment of patients with locally advanced stages of primary Larynx Cancer and in the cases when recurrence is treated after radiotherapy or chemoradiotherapy. Leading position in the combined treatment of locally advanced carcinoma of the Larynx belongs to surgical treatment. Published reports of salvage treatment for Larynx reconstruction after partial laryngectomy are available, some of them using structures of the Larynx itself, but few aimed on a search of new materials and techniques for sparing laryngeal surgery.Possibility to perform a sparing surgery depends on several factors, including, the possibility of adequate laryngeal replacement after an extensive resection. Meanwhile, surgery improvement goes along with differentiated choice of an adequate degree of surgical intervention. However, the functional results of such surgeries do not always satisfy both patients and professionals, if we consider that large fragments of the organ have to be resected in locally advanced Larynx Cancers.The Larynx reconstruction is a complex goal, it can be explained by several factors. First of all, this is topographic and anatomical feature of the Larynx since it is located next to the digestive tract. Fixation and immobilization of the Larynx is hard to perform as it is a mobile organ when swallowing, speaking etc. Secondly, there are no commercially produced endografts for wide clinical practice. Thirdly, there are high demands regarding the material selection for the replacement. This study aimed to present the new technique of sparing surgery in patients with laryngeal Cancer.Methods: Totally 120 patients with laryngeal Cancer were observed with stage grouping T2-3N0-1M0 (Т1N0M0 – 14, Т2N0M0 – 40, T3N0M0 – 58, T2N1M0 – 8). Most of them (118, 98.3%) were males where patients’ age ranged from 32 to 70 years (Tab. 1). The maximum number of patients (78%) was in 40–60 years group. Not all of those in the laryngeal Cancer group were newly diagnosed and they received previous treatment. Informed consent was obtained from each patient. The subsites of laryngeal Cancer were the glottis in 17 cases, the supraglottic-glottis in 45 cases and the transglottic in 58 cases.The intervention depended on the location and extent of the tumor process. Standard volume of resection, extended resection, combined resection, subtotal resection were basic types of surgery. Most of laryngeal resections were front-lateral (117, 98%) and there were only three (2%) subtotal ones. Surgeries on the primary focus were combined with cervical lymph node dissection in eight patients (6.6%). The essence of the resection is to remove Larynx structures which are affected by neoplastic process as a single unit including mucosa, submucosa layer, muscles, thyroid cartilage with the inner perichondrium into the volume of cut out tissue.Both the creation of laryngeal frame using the endograft made of superelastic TiNi-based alloy mesh and the providing of the inner lining of the recovered Larynx is the basis of sparing technique regarding the Larynx prosthetics.Producing of original design endograft made of superelastic TiNi-based alloy mesh was performed individually for each patient using the data acquired by helical CT of the Larynx, laryngoscopy and volume of upcoming surgery. The endograft is a framework made of two twisted superelastic TiNi-based wires (TN-10 brand alloy) having 0.4 mm dia provided by Kang&Park Medical Co. (S. Korea). It is further covered with superelastic TiNi-based alloy mesh. The mesh is constructed of knitted filaments made of the same TN-10 brand alloy wire, which stress-strain behavior is identical to human body tissues. This mesh is thin, flexible and laminate designed for the repair of hernias, ruptured tendons, and other fascial deficiencies. This material, when used in vivo, has been reported to be non-reactive and to retain its properties indefinitely in wide clinical use. The mesh 0.1-0.15 mm thick is knitted by a process which interlinks each fiber junction and provides for superelasticity in any direction. Such design enables the mesh to be cut off into any desired shape or size without unraveling. The fiber junctions are not subject to the same work fatigue showing by more rigid polypropylene or metal-based meshes. This any-directional superelastic property allows the mesh to be easily adapted to various stresses appeared in the human body. The mesh mentioned has been also commercially produced by Kang&Park Medical Co. (S. Korea).This endograft design shows the superelastic behavior (at the time of physiological movements of the Larynx during swallowing, breath and speech) recovering the shape of frame. The endograft described is radio-opacifying, unlike other endografts e.g. polymer-based endografts. This property makes it possible to control the position over time.We used local muscle tissues (platysma) or muscle-flap prefabrication technique (flap of the rectus abdominis) for formation of the inner lining. 15 patients with laryngeal Cancer (stage Т2-3N0M0) have been treated by using the technique.All patients underwent different types of sparing surgeries (front-lateral laryngectomy – 3 cases, frontal laryngectomy – 6 cases, subtotal laryngectomy – 6 cases) with simultaneous replacement with the endograft described. These surgeries were performed in 5 patients (Т2N0M0 - 2 and Т3N0M0 - 3 cases) in terms of combined treatment (with preoperative radiotherapy dose 40 Gy). 10 patients (rT2N0M0 – 3 and rT3N0M0 - 7 cases) had recurrent laryngeal Cancer after radical radiotherapy. In 9 cases we used the platysma flap and in 6 cases we did muscle-flap prefabrication technique (flap of the rectus abdominis) with inclusion of the endograft for formation of the inner lining of the Larynx wall. Muscle-flap prefabrication technique consists of an implantation of pre-created superelastic TiNi mesh into the rectus abdominis muscle. When the time of prefabrication (about 3–4 weeks) was over we performed reconstructive surgery using this prepared muscle flap with inclusion of the endograft. Such autograft was included in the blood flow by means of microvascular anastomosis applied between the recipient and donor vessels (as a rule - superior thyroid artery and vein).Results: Analyzing sparing operations using endografts described we achieved the following functional results. Voice function was completely saved in 112 (93.3%) cases and partially in 8 ones (6.7%). Respiratory function was fully restored in 106 (88.3%) patients, in 14 cases (11.7%) the cannula was not taken out from patients due to scar changes. The protective function of the Larynx was saved in 116 (96.6%) patients. There was a temporary partial impairment of Larynx protective function in four patients (3.4%).Monitoring of the reconstructed Larynx was traditionally based on laryngeal endoscopy, spiral CT study and scintigraphy. Laryngoscopy in 14 days after the operation showed the endograft coated with fibrin plaque with isolated islets of pink granulation tissue "approaching" from the periphery. Almost the entire surface of the endograft was coated with an even layer of tender granulation tissue in 30 days after the surgery. Mucous membrane on endograft edges is bright pink and shiny without signs of inflammation. In 3 months after the surgery - glottic chink lumen was not deformed, it was free, and endograft surface was covered with a tender pale pink mucous membrane. Entire endograft was coated with thin even layer. Morphological study of mucosa fragments taken from the surface of endografts in 12 months after surgery revealed the following: layered non-squamous flat epithelium with proper stratification; poorly expressed hyperplasia of basal cells. Such condition of epithelium proves complete reparative regeneration of mucosa without any signs of pathology. Impairment of epithelial differentiation was not detected in any site of mucosa studied.Analysis of complications allowed to define that aftereffects as local inflammatory reactions nearby prosthetics region (perichondritis of Larynx cartilages, mucosal edema of the Larynx) were observed in 16 cases (13.3%) in postoperative period. These complications required additional medical treatment (antibiotics, photoradiotherapy, etc.). In particular, laryngectomy was performed in one case due to intractable laryngeal chondroperichondritis, severe pain and persistent impairment of swallowing function. In our study, laryngectomy was performed in 14 cases (11.7%) due to the continued growth of tumor during the first year after surgery according to the technique offered. Three (2.5%) patients died because of Cancer progression. The 5-year and overall recurrence-free survival rates of all 120 patients were 83% and 76%, respectively.Evaluation of results when we used sparing surgery applying modified approaches and endografts has shown that there was an exact match of endograft topology and Larynx defects appeared. Helical computed tomography of the Larynx has proven the correct state of the endograft and no migration in all the cases.Conclusion: The developed sparing surgical treatment using TiNi-based endografts has shown the efficiency of laryngeal reconstruction in adverse conditions (trophic-inflammatory changes of the Larynx after radiotherapy). Given the nature of techniques and postoperative course, we have formulated our indications for each method of reconstruction.Using the flap of the platysma is more preferable in small reconstructions (after anterolateral laryngectomy). This method has the advantage of simplicity and one-stage reconstruction. Prefabrication method allows to get a prototype of the layerwise wall of the laryngeal cavity having the mucosal lining and vascular continuity. This method is preferable in reconstructing the large defect (subtotal laryngectomy) in patients with severe post-radiation changes in the Larynx and the neck, as well as in case of postpone reconstruction.The offered method of sparing treatment was finally turned out to be economically justified regarding treatment cost minimization. The results of functional rehabilitation of patients after surgical treatment using TiNi-based endografts permit to show preference for such surgery despite the fact that cannula was not taken out from a certain number of patients and there was a continued growth of tumor and recurrence. Compliance with the paradigm of malignant tumor metastasis and ablastics enables to hope that the number of complications will be reduced. Endografts made of TiNi-based mesh can adequately restore the frame function of the Larynx, without postoperative aggravation. Both the local and displaced (prefabrication technique) tissues can be used in reconstruction of the inner lining of the Larynx. Careful selection of patients, indications and replacement technique is necessary for such sparing surgery to be performed.-----------------------------------------Cite this article as: Denis K, Marat M, Timofey C, Ji-Hoon K, Georgiy C, Valentina H, Victor G. The use of TiNi-based endografts in Larynx Cancer patients. Int J Cancer Ther Oncol 2015; 3(4):3404.[This abstract was presented at the BIT’s 8th Annual World Cancer Congress, which was held from May 15-17, 2015 in Beijing, China.
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sparing surgery with the use of tini based endografts in Larynx Cancer patients
Journal of Surgical Oncology, 2015Co-Authors: Marat Muhamedov, Denis Kulbakin, Timofey Chekalkin, V E Gunther, Evgeniy Choynzonov, Valentina HodorenkoAbstract:Background and Objectives Purpose of this study was to improve a technique of sparing surgery in patients with laryngeal Cancer by using TiNi-based endografts and to achieve well functional and oncological results after laryngectomy. Methods Totally 120 patients with laryngeal Cancer were observed (T2–3N0–1M0). We have developed a method of laryngeal reconstruction using TiNi-based endografts. All endografts show the superelastic behavior recovering the shape. All patients have undergone different types of sparing surgeries with simultaneous replacement with endografts. Results Voice function was completely saved in 112 cases and partially in 8 ones. Respiratory function was fully restored in 106 patients. The protective function of the Larynx was achieved in 116 patients. Conclusion The technique allowed to achieve well oncological (the 5-year and overall recurrence-free survival rates of all 120 patients were 83% and 76%, respectively) and functional (Larynx function was saved in 93% of cases) outcomes after extensive and subtotal resections in patients with locally distributed Larynx Cancer. J. Surg. Oncol. 2015 111:231–236. © 2014 Wiley Periodicals, Inc.
Simone Benhamou - One of the best experts on this subject based on the ideXlab platform.
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dna repair gene xrcc2 and xrcc3 polymorphisms and susceptibility to Cancers of the upper aerodigestive tract
International Journal of Cancer, 2004Co-Authors: Jarno Tuimala, Alain Sarasin, Simone Benhamou, Christine Bouchardy, Pierre Dayer, Ari HirvonenAbstract:Cigarette smoke can generate reactive oxygen species, which are capable of inducing double-strand breaks (DSBs) in DNA. Polymorphisms in XRCC2 and XRCC3 genes, involved in DSBs repair pathways, may alter an individual's susceptibility to smoking-related Cancers. We investigated the effect of XRCC2 Arg188His and XRCC3 Thr241Met polymorphisms in Cancer proneness in 121 oral/pharynx Cancer cases, 129 Larynx Cancer cases and 172 nonCancer controls, all Caucasian smokers. The XRCC2 His-allele was associated with a significantly increased risk of pharyngeal Cancer (OR=2.9, 95% CI: 1.3–6.2). No significant associations were observed between the XRCC3 Thr241Met polymorphism and overall risk of developing UADT Cancers. However, quite opposite to the expectations, a reduced risk of supraglottic Cancer was found for carriers of the XRCC3 Met variant allele (OR=0.3, 95% CI: 0.2–0.7). These findings provide evidence for the view that polymorphisms in DNA repair genes may modify individual susceptibility to smoking-related Cancers. © 2004 Wiley-Liss, Inc.
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Larynx Cancer risk in relation to glutathione s transferase m1 and t1 genotypes and tobacco smoking
Cancer Epidemiology Biomarkers & Prevention, 1998Co-Authors: Nadejda Jourenkova, Simone Benhamou, Christine Bouchardy, Pierre Dayer, M Reinikainen, Ari HirvonenAbstract:Glutathione S-transferase (GST) isoenzymes are involved in the detoxification of several tobacco smoke-derived carcinogens. It is thus conceivable that deficiency in GST activity due to homozygous deletion of the GSTM1 and GSTT1 genes (the null genotypes) may modulate susceptibility to smoking-induced Cancers. The effects of the GSTM1 and GSTT1 null genotypes on laryngeal Cancer risk were evaluated using peripheral blood DNA from 129 Larynx Cancer patients and 172 nonCancer controls, all of whom were regular smokers. Increased Larynx Cancer risk was related to the GSTM1 null genotype [odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.0-2.8]. The OR associated with the GSTT1 null genotype was increased, although not significantly (OR = 1.4, 95% CI = 0.7-2.9). Individuals with concurrent lack of GSTM1 and GSTT1 genes had a doubled, although not significant, risk for Larynx Cancer when compared with those having at least one of these genes (OR = 2.0, 95% CI = 0.8-5.2) and had almost a 3-fold risk (OR = 2.7, 95% CI = 1.0-7.4) when compared with those with both genes. Moreover, a significant interaction between the GSTM1 genotype and levels of tobacco consumption (P < 0.05) was found; the GSTM1 null genotype was associated with an increased risk of Larynx Cancer among smokers of 20 g/day or less (OR = 2.9, 95% CI = 1.3-6.3) but not among heavier smokers (OR = 1.0; 95% CI = 0.5-2.0). In contrast, the GSTT1 null genotype posed an increased, although not significant, risk among long-term smokers (OR = 2.3, 95% CI = 0.9-5.4).
