Smokeless tobacco and increased risk of hypopharyngeal and laryngeal cancers: A multicentric case–control study from India

Abstract

Hypopharyngeal and laryngeal cancers are among the most common cancers in India. In addition to smoking, tobacco chewing may be a major risk factor for some of these cancers in India. Using data from a multicentric case–control study conducted in India that included 513 hypopharyngeal cancer cases, 511 laryngeal cancer cases and 718 controls, we investigated smoking and chewing tobacco products as risk factors for these cancers. Bidi smoking was a stronger risk factor compared to cigarette smoking for cancer of the hypopharynx (ORbidi 6.80 vs. ORcig 3.82) and supraglottis (ORbidi 7.53 vs. ORcig 2.14), while the effect of the 2 products was similar for cancer of the glottis (ORbidi 5.32 vs. ORcig 5.74). Among never‐smokers, tobacco chewing was a risk factor for hypopharyngeal cancer, but not for laryngeal cancer. In particular, the risk of hypopharyngeal cancer increased with the use of Khaini (OR 2.02, CI 0.81–5.05), Mawa (OR 3.17, CI 1.06–9.53), Pan (OR 3.34, CI 1.68–6.61), Zarda (OR 3.58, CI 1.20–10.68) and Gutkha (OR 4.59, CI 1.21–17.49). A strong dose‐response relationship was observed between chewing frequency and the risk of hypopharyngeal cancer (ptrend < 0.001). An effect of alcohol on cancer of the hypopharynx and supraglottis was observed only among daily drinkers (OR 2.22, CI 1.11–4.45 and OR 3.76, CI 1.25–11.30, respectively). In summary, this study shows that chewing tobacco products commercially available in India are risk factors for hypopharyngeal cancer, and that the potency of Bidi smoking may be higher than that of cigarette smoking for hypopharyngeal and laryngeal cancers. © 2007 Wiley‐Liss, Inc.

Epidemiological Evaluation of Laryngeal Cancer Incidence in Kazakhstan for The Years 1999-2009

“…Both increasing duration and intensity of smoking are important (Ramroth et al, 2011) and involuntary smoking exposure is also a factor (Lee et al, 2008). Smokeless chewing tobacco, however, does not appear to be of significance (Sapkota et al, 2007).…”

Laryngeal Cancer in Kazakhstan - Ethnic, Age and Gender Differences over Time

“…Both increasing duration and intensity of smoking are important (Ramroth et al, 2011) and involuntary smoking exposure is also a factor (Lee et al, 2008). Smokeless chewing tobacco, however, does not appear to be of significance (Sapkota et al, 2007) Excessive consumption of alcohol, particularly alcoholic beverages increases the risk of cancer in sites like the larynx (Islami et al, 2010;Tavani et al, 2012). In one study approximately 39% of cases appeared attributable to the interaction between alcohol and tobacco (Hashibe et al, 2007).…”

Dietary risk factors for hypopharyngeal cancer in India

“…The four participating centers were the Gujarat Cancer and Research Institute in Ahmadabad, the Gandhi Medical College in Bhopal, the Chittaranjan National Cancer Institute in Kolkata, and the Cancer Institute (WIA) in Chennai. Details of the study have been described elsewhere [20]. In brief, case subjects were selected from all incident pathologically confirmed cases of disease among patients presenting at participating hospitals from 2001 to 2004.…”