Management Of Squamous Cell Carcinoma Research Articles

Long-read sequencing of oropharyngeal squamous cell carcinoma tumors reveal diverse patterns of high-risk Human Papillomavirus integration.

In North America and in most European countries, Human Papillomavirus (HPV) is responsible for over 70% of oropharyngeal squamous cell carcinomas. The burden of OPSCC, in high-income countries, has been steadily increasing over the past 20 years. As a result, in the USA and in the UK, the burden of HPV-related oropharyngeal squamous cell carcinoma in men has now surpassed that of cervical cancer in women. However, the oncogenic impact of high-risk HPV integration in oropharyngeal squamous cell carcinomas hasn't been extensively studied. The present study aimed to explore the patterns of HPV integration in oropharyngeal squamous cell carcinomas and to assess the feasibility and reliability of long-read sequencing technology in detecting viral integration events in oropharyngeal head and neck cancers. A cohort of eight HPV-positive OPSCC pre-treatment patient tumors (four males and four females), were selected. All patients received a p16INK4A positive OPSCC diagnosis and were treated at the McGill University Health Centre, a quaternary center in Montreal. A minimum of 20mg of tumor tissue was used for DNA extraction. Extracted DNA was subjected to Nanopore long-read sequencing to detect and analyze for the presence of high-risk HPV sequences. PCR and Sanger sequencing experiments were performed to confirm Nanopore long-read sequencing readings. Nanopore long-read sequencing showed that seven out of eight patient samples displayed either integrated or episomal high-risk HPV sequences. Out of these seven samples, four displayed verifiable integration events upon bioinformatic analysis. Integration confirmation experiments were designed for all four samples using PCR-based methods. Sanger sequencing was also performed. Four distinct HPV integration patterns were identified: concatemer chromosomal integration in a single chromosome, bi-chromosomal concatemer integration, single chromosome complete integration and bi-chromosomal complete integration. HPV concatemer integration also proved more common than full HPV integration events. Long-read sequencing technologies can be effectively used to assess HPV integration patterns in OPSCC tumors. Clinically, more research should be conducted on the prognostication value of high-risk HPV integration in OPSCC tumors using long-read sequencing technology.

Human papillomavirus-associated cancer incidence by disaggregated Asian American, Native Hawaiian, and other Pacific Islander ethnicity.

Asian Americans and Native Hawaiians and other Pacific Islanders have suboptimal human papillomavirus (HPV) vaccination and cancer screening rates. Asian Americans and NHPIs are often aggregated, masking disparities characterized by varying colonization and immigration patterns and cultural and religious beliefs between populations and ethnicities. We examined the incidence of HPV-associated cancers across disaggregated Asian American and NHPI ethnicities. Using the Surveillance, Epidemiology, and End Results Detailed Asian/Pacific Islander database, we calculated 1990 to 2014 sex-specific, age-standardized HPV-associated cancer incidence of cervical carcinoma, oropharyngeal squamous cell carcinoma (SCC), vulvar SCC, vaginal SCC, anal SCC, and penile SCC by ethnicity: Asian Indian and Pakistani, Chinese, Filipino, Japanese, Kampuchean, Korean, Laotian, Native Hawaiian, other Pacific Islander, and Vietnamese. Trends by calendar period (1990 to 1996, 1997 to 2002, 2003 to 2008, 2009 to 2014) were estimated using Joinpoint regression. The most common HPV-associated cancer was cervical carcinoma in women and oropharyngeal SCC in men. During 1990 to 2014, cervical carcinoma incidence per 100 000 ranged from 4.5 (Asian Indian and Pakistani) to 20.7 (Laotian). Cervical carcinoma incidence only statistically significantly declined for Asian Indian and Pakistani, Filipino, Korean, Laotian, and Vietnamese women (range = 19.9% to 44.1% decline per period). Among men, oropharyngeal SCC incidence per 100 000 ranged from 1.1 (Chinese) to 5.1 (Native Hawaiian). Oropharyngeal SCC incidence only statistically significantly increased (31.0% increase per period) for Japanese men. Heterogeneity across ethnicities were observed for other cancer sites. HPV-associated cancer incidence varied widely between Asian Americans and NHPIs and by ethnicity, underscoring the need for improved data capture of ethnic groups in research and more tailored interventions to better address health disparities between Asian American and NHPI populations.

Incidence trends and spatial distributions of lung adenocarcinoma and squamous cell carcinoma in Taiwan

Lung cancer is the second most common cancer in Taiwan. After Taiwan implemented the Tobacco Hazards Prevention Act in 1997, smoking rates declined. However, the incidence rates of lung cancer for both sexes are still increasing, possibly due to risk factors other than smoking. We used age–period–cohort analysis to examine the secular trends of lung cancer incidence rates by histological type in Taiwan. A stabilized kriging method was employed to map these lung cancer incidence rates. Lung adenocarcinoma incidence rates increased, but lung squamous cell carcinoma incidence rates decreased, for both the sexes in recent birth cohorts, particularly in women. In Taiwan, the hotspots of lung adenocarcinoma incidence rates were in the northern, northeastern, and western coastal areas; the incidence rates increased rapidly in the western and southern coastal regions and southern mountainous regions. The high incidence rates of lung squamous cell carcinoma in men were in the southwestern and northeastern coastal areas. The incidence rates rapidly increased in the central and southern coastal and mountainous regions. For both sexes in Taiwan, lung squamous cell carcinoma incidence rates declined from 1997 to 2017, but lung adenocarcinoma increased. The increased incidence rates of lung adenocarcinoma may be related to indoor and outdoor air pollution. Some areas in Taiwan have increasing lung cancer incidence rates, including the northwestern and southern coasts and mountains, and warrant particular attention.

Clinical and histopathological pattern of lung cancer in Morocco.

lung cancer is the most common cancer and the leading cause of cancer death worldwide. This study aimed to provide an overview of the epidemiology of primary lung cancer in Morocco. The distribution of histological subtypes by sex and smoking status was also assessed. this was a retrospective and descriptive study using medical records of patients with primary lung cancer, diagnosed at two university hospitals in Morocco between 2014 and 2017. a total of 606 patients (average age = 58.5 ± 10.64 years, men = 521) were included. Four hundred and forty-three men had a history of smoking against sex women. Most patients (85.68%) had respiratory symptoms at diagnosis. Over half of patients (53.03%) had a performance status <2 and 38.94% had at least another pulmonary disease at presentation. Chronic obstructive pulmonary disease (COPD) and tuberculosis were present in 23.43% and 18% of patients, respectively. The majority (72.27%) of men practiced an occupation associated with a significant risk of lung cancer. Adenocarcinoma was the main histological type in our series with 60.40%. Most (79.55%) patients were diagnosed at stage IV. Only 7.83% of patients benefited from surgery. The distribution of histological subtypes by sex and smoking habits showed that adenocarcinoma was more frequent in women (p=0.011), and squamous cell carcinoma in men (p=0.014). No differences between smokers and non-smokers were noted. our results showed a decrease in the age of diagnosis and a late stage of the disease. Adenocarcinoma was the most frequent histological type.

Incidence of HPV-related Anogenital Intraepithelial Neoplasia and Cancer in Men With Diabetes Compared With the General Population.

Diabetes may increase risk of human papillomavirus (HPV)-related precancer and cancer. We estimated incidence of penile and anal high-grade intraepithelial neoplasia (hgPeIN, hgAIN) and squamous cell carcinoma (SCC) in men with diabetes compared with the entire Danish male population without diabetes. In this registry-based cohort study, we included all men born 1916-2001 and residing in Denmark (n = 2,528,756). From nationwide registries, we retrieved individual-level information on diabetes, educational level, and diagnoses of hgPeIN, hgAIN, penile SCC, and anal SCC. We used Poisson regression models to estimate incidence of hgPeIN, hgAIN, penile SCC, and anal SCC as a function of diabetes status, attained age, calendar period, and education. We estimated incidence rate ratios (IRRs) of each outcome in men with diabetes compared with nondiabetic men, both for diabetes overall and separately for type 1 (T1D) and type 2 diabetes (T2D). Men with diabetes had increased incidence rate of penile SCC compared with nondiabetic men (IRR = 1.5, 95% CI = 1.2, 1.9). We saw similar trends for anal SCC, hgPeIN, and hgAIN. The combined incidence rate of penile and anal SCC was increased in men with T2D (IRR = 1.5, 95% CI = 1.3, 1.8), but not with T1D (IRR = 0.53, 95% CI = 0.20, 1.4) compared with men without diabetes. The incidence of penile and anal high-grade intraepithelial neoplasia and SCC in men with diabetes was increased compared with men without diabetes. For penile and anal SCCs, this was primarily due to an increased risk in men with T2D.

National incidence of eyelid cancer in Ireland (2005-2015).

We report on the incidence of cutaneous eyelid tumours in Ireland over the 11-year-period from 2005 to 2015, we identify associations between demographic factors and cutaneous eyelid tumour risk. Skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), melanoma, and other cancers, located on the eyelid or canthus according to ICD-10 coding, as registered by the National Cancer Registry of Ireland (NCRI), were captured from the period 2005 to 2015. Age standardised rates (ASR) were calculated according to the European Standard Population (2013). Longitudinal data analysis using linear regression, and associations with age and sex were evaluated with the statistics program R. There were 4824 patients diagnosed with eyelid BCC during the study period, the ASR in men and women was mean 15.87 and 13.49 per 100,00, respectively. The relative risk for eyelid BCC in men compared with women was 1.18, age was associated with incidence. There were 528 patients diagnosed with SCC; the ASR of eyelid SCC in men and women was 2.10 and 1.39 per 100,000, respectively, and increased in women annually (β = 0.07, p = 0.0005). The relative risk for eyelid SCC in men compared with women was 1.51, and age was exponentially associated with SCC. Melanoma and other eyelid tumours were uncommon-50 and 55 cases, respectively. Incidence of both BCC and SCC increases with age and male sex. The incidence of eyelid SCC is increasing in women, and under age 50, eyelid BCC is more common in women than men. We describe the recent incidence of eyelid cancers in Ireland, from National Cancer Registry Data. We find eyelid BCC, and also SCC, are associated with increased age. Rate of eyelid SCC is increasing in women.

Profile of patients and factors related to the clinical staging of oral squamous cell carcinoma

The aim of the present study was to identify the profile of patients diagnosed with oral squamous cell carcinoma (SCC) and factors associated with the clinical stage of the disease. A cross-sectional study was conducted with a sample of 293 medical charts of patients with SCC treated at an oncology reference center in the city of Campina Grande (Brazil) between 2000 and 2006. Descriptive and inferential statistics were performed with robust Poisson regression (α=5%). Males (56.6%), non-white individuals (49.0%) and individuals over than 60 years of age (74.1%) were the most affected by SCC. The tongue (35.1%) and palate (21.5%) were the most common sites. A large portion of the patients were smokers (37.6%) and 60.2% were in an advanced stage of the disease. Clinical staging was not associated with sex, age, skin color or drinking and/or smoking habits. There was a higher incidence of SCC in men, older patients, non-white individuals and smokers. Clinical staging was not associated with the variables analyzed.

Report on the incidence of squamous cell carcinomas affecting the eyelids in England over a 15-year period (2000–2014)

AimsThe authors report on trends in the incidence of squamous cell carcinoma (SCC) affecting the eyelids in England over a 15-year period and identify associations between demographic factors and SCC...

Residual neck disease management in squamous-cell carcinoma of the head and neck treated with radiotherapy plus cetuximab.

Management of residual neck disease (RND) is one of the unsolved points after bio-radiotherapy (BRT) in loco-regional advanced squamous-cell carcinoma of the head and neck (SCCHN). The aims of the study were to characterize the radiological pattern of response by computed tomography (CT) and to assess the role of positron-emission tomography (PET)/CT in this setting for a better decision-making in the indication of neck dissection (ND). We retrospectively reviewed 202 patients consecutively diagnosed with node-positive SCCHN (N1: 24; N2: 152; N3: 26) who had been treated with concomitant radiotherapy and cetuximab with or without previous induction chemotherapy between 2006 and 2013. Radiological evaluation after treatment was assessed by standard criteria using CT and in addition by PET/CT when RND was suspected in cases from 2010. There were 42 (21%) patients who achieved complete response of the primary tumor persisting RND by CT. From this group, 24 patients were managed without PET/CT, leading to the performance of ND in 22 (92%). On the other hand, 18 patients underwent PET/CT and ND was performed in only 6 (33%). The overall survival was not different between both groups (p=0.32). After histological examination and follow-up, PET/CT obtained a positive predictive value of 56% and a negative predictive value of 89%. Radiological response after BRT is similar to that after treatment with chemo-radiotherapy, thereby validating in this scenario the accepted CT criteria to define complete response of the neck. However, when RND is suspected by CT, PET/CT is useful to prevent unnecessary ND.

The use of corticosteroids in patients with COPD or asthma does not decrease lung squamous cell carcinoma.

BackgroundAsthma and COPD (chronic obstructive pulmonary disease) lead to persistent airway inflammation and are associated with lung cancer. The objective of the study was to assess the relationship between inhaled (ICS) and oral corticosteroid (OCS) use, and risk of lung squamous cell carcinoma (SqCC).MethodsThis study was a nested case–control study. Patients with newly diagnosed asthma or COPD between 2003 and 2010 were identified from the National Health Insurance Database. Cases were defined as patients diagnosed with SqCC after enrollment. For each case, four control individuals who were randomly matched for sex and age and date diagnosis of asthma or COPD were selected.ResultsFrom the 1,672,455 eligible participants, 793 patients with SqCC were matched with 3,172 controls. The odds ratios (ORs) of SqCC in men who received high and low-dose ICS were 2.18 (95 %CI, 1.56–3.04) and 1.77 (1.22–2.57), respectively. Similarly, the ORs were 1.46 (95 %CI, 1.16–1.84) and 1.55 (95 %CI, 1.22–1.98) for men who were placed on low and high dose OCS. However, there was no significant association between cumulative ICS and/or OCS and risk of SqCC in women. Recent dose increase in corticosteriod was significantly associated with risk of SqCC. Specifically, among men, the ORs for SqCC were 8.08 (95 %CI, 3.22–20.30) for high-dose ICS + OCS, 4.49 (95 % CI, 2.05–9.85) for high-dose ICS, and 3.54 (95 % CI, 2.50–5.01) for high-dose OCS treatments, respectively. The OR for SqCC in women who received high-dose OCS was 6.72 (95 %CI, 2.69–16.81).ConclusionCorticosteroid use did not decrease SqCC in patients with asthma or COPD. Recent dose increase in corticosteroids was associated with SqCC.

Residual Neck Disease (Rnd) Management in Squamous-Cell Carcinoma of the Head and Neck (Scchn) Treated with Radiotherapy (Rt) Plus Cetuximab (C)

Residual Neck Disease (Rnd) Management in Squamous-Cell Carcinoma of the Head and Neck (Scchn) Treated with Radiotherapy (Rt) Plus Cetuximab (C)

0225 Cancer, mortality and acute myocardial infarction in workers exposed to respirable crystalline silica dust at a Swedish porcelain factory

ObjectivesExposure to silica dust is a health hazard in the ceramic industry. We studied cancer, mortality and acute myocardial infarction (AMI) among workers at a Swedish porcelain factory.MethodAnnual average of...

RNASEL and MIR146A SNP-SNP interaction as a susceptibility factor for non-melanoma skin cancer.

Immunity and inflammatory pathways are important in the genesis of non-melanoma skin cancers (NMSC). Functional genetic variation in immune modulators has the potential to affect disease etiology. We investigated associations between common variants in two key regulators, MIR146A and RNASEL, and their relation to NMSCs. Using a large population-based case-control study of basal cell (BCC) and squamous cell carcinoma (SCC), we investigated the impact of MIR146A SNP rs2910164 on cancer risk, and interaction with a SNP in one of its putative targets (RNASEL, rs486907). To examine associations between genotype and BCC and SCC, occurrence odds ratios (OR) and 95% confidence intervals (95%CI) were calculated using unconditional logistic regression, accounting for multiple confounding factors. We did not observe an overall change in the odds ratios for SCC or BCC among individuals carrying either of the RNASEL or MIR146A variants compared with those who were wild type at these loci. However, there was a sex-specific association between BCC and MIR146A in women (ORGC = 0.73, [95%CI = 0.52–1.03]; ORCC = 0.29, [95% CI = 0.14–0.61], p-trend<0.001), and a reduction in risk, albeit not statistically significant, associated with RNASEL and SCC in men (ORAG = 0.88, [95%CI = 0.65–1.19]; ORAA = 0.68, [95%CI = 0.43–1.08], p-trend = 0.10). Most striking was the strong interaction between the two genes. Among individuals carrying variant alleles of both rs2910164 and rs486907, we observed inverse relationships with SCC (ORSCC = 0.56, [95%CI = 0.38–0.81], p-interaction = 0.012) and BCC (ORBCC = 0.57, [95%CI = 0.40–0.80], p-interaction = 0.005). Our results suggest that genetic variation in immune and inflammatory regulators may influence susceptibility to NMSC, and novel SNP-SNP interaction for a microRNA and its target. These data suggest that RNASEL, an enzyme involved in RNA turnover, is controlled by miR-146a and may be important in NMSC etiology.

Occupational asbestos exposure is associated with pharyngeal squamous cell carcinoma in men from the greater Boston area

ObjectivesAsbestos is the name given to a group of naturally occurring silicate mineral fibres that were widely used in industry during the 20th century due to their desirable physical properties....

Neonatal circumcision and invasive squamous cell carcinoma of the penis: a report of 3 cases and a review of the literature

Neonatal circumcision is widely considered to have a protective effect against the development of squamous cell carcinoma of the penis in later life. We report 3 cases of squamous cell carcinoma in men who were circumcised as neonates. The 3 men, aged 49, 55 and 64 years, presented for consideration of brachytherapy. The tumour stage was T3 in 1 case and T1 in the others. The tumours were moderately differentiated in 2 cases and well differentiated in 1 case. All 3 men had a remote history of penile condylomata acuminatum 20-30 years earlier. Oncogenic human papillomavirus (HPV) was found in the tumour specimen in 1 case. All 3 were treated with brachytherapy to the primary tumour on the glans. In 2 cases, subsequent staging inguinal node dissection was indicated because of the grade and stage of the primary tumour. A history of remote HPV infection should increase the index of suspicion for any nonhealing penile lesion, despite a history of neonatal circumcision.

Anal cancers attributed to human papillomavirus are more common in areas in Victoria, Australia, with higher HIV notifications

Anal cancer is more common in men who have sex with men with HIV. We aimed to determine if there was an association between anal squamous cell carcinoma (SCC) and HIV notifications in men in Victoria, Australia, at a population level. We calculated the male age-standardised incidence rates for anal SCC, brain cancer and colon cancer for each local government area (LGA) in Victoria from 1982 to 31 December 2010 using the Victorian Cancer Registry. Male HIV rates in each LGA were calculated using the Victorian HIV Registry. There were 288 men diagnosed with anal SCC, 8793 with brain cancer and 23?938 with colon cancer in 57 LGAs. There were 3163 men notified with HIV during the same period in the same LGAs (range: 4-435 per LGA). There was a significant positive correlation (r=0.45, P<0.001, r(2)=0.20) between the age-standardised rate of anal SCC and the rate of HIV notifications in men in each LGA but no correlation between the male age-standardised rate of colon (Pearson's r=-0.11, P=0.40) or brain (r=-0.05, P=0.71) cancers, and the rate of HIV. The rate of anal cancer was ~50% higher in LGAs with the highest HIV notification rate (incidence rate ratio=1.47; 95% confidence interval: 1.10-1.97). At a population level, about one in five cases (r(2)=0.20) of anal SCCs in men are explained by the rate of HIV notifications in that LGA.

Red and processed meat consumption and the risk of esophageal and gastric cancer subtypes in The Netherlands Cohort Study

Prospective data on red and processed meat in relation to risk of subtypes of esophageal and gastric cancer are scarce. We present analyses of association between red and processed meat and the risk of esophageal and gastric cancer subtypes within The Netherlands Cohort Study on Diet and Cancer. 120 852 individuals aged 55-69 years were recruited in 1986, and meat intake was assessed using a 150-item food frequency questionnaire. After 16.3 years of follow-up, 107 esophageal squamous cell carcinomas, 145 esophageal adenocarcinomas, 163 gastric cardia adenocarcinomas, 489 gastric non-cardia adenocarcinomas, and 3923 subcohort members were included in a case-cohort analysis. Processed as well as red meat intake was positively associated with esophageal squamous cell carcinoma in men. Hazard ratios for highest versus lowest quintile of processed and red meat were 3.47 [95% confidence intervals (CI): 1.21-9.94; P for trend: 0.04] and 2.66 (95% CI: 0.94-7.48; P for trend: 0.06), respectively. No association was seen for adenocarcinomas or gastric cancer subtypes or for any of the four subtypes among women. Our findings suggest that red and processed meat consumption is associated with increased risk of esophageal squamous cell carcinoma in men but not with cancers of other esophageal and gastric subtypes.

Molecular modelling studies of new potential human DNA polymerase α inhibitors

The human polymerase α (pol α) is a promising target for the therapy of cancer e.g. of the skin. The authors recently built a homology model of the active site of human DNA pol α. This 3D model was now used for molecular modelling studies with eight novel analogues of 2-butylanilino-dATP, which is a highly selective nucleoside inhibitor of mammalian pol α. Our results suggest that a higher hydrophobicity of a carbohydrate side chain (pointing into a spacious hydrophobic cavity) may enhance the strength of the interaction with the target protein. Moreover, acyclic acyclovir-like derivatives outperformed those with a sugar-moiety, indicating that structural flexibility and higher conformational adaptability has a positive effect on the receptor affinity. Cytotoxicity tests confirmed our theoretical findings. Besides, one of our most promising compounds in the molecular modelling studies revealed high selectivity for the SCC-25 cell line derived from squamous cell carcinoma in man.

The relationship between stage 1 and 2 non-small cell lung cancer and lung function in men and women.

BackgroundReduced forced expiratory volume in one second (FEV1) has been linked to non small cell lung cancer (NSCLC). However, it is unclear whether all or only certain histological subtypes of NSCLC are associated with reduced FEV1. Moreover, there is little information on whether gender modifies this relationship. Using a large tissue registry, we sought to determine the relationship between FEV1 and subtypes of NSCLC and determine whether this relationship is modified by gender.MethodsWe used data from patients who underwent tumor resection for NSCLC at a teaching hospital in Vancouver and had various pre-operative clinical measurements including FEV1. We divided the cohort into quartiles of predicted FEV1 and using both logistic and linear regression modeling techniques determined whether FEV1 was related to the occurrence of adeno or squamous cell carcinoma in men and women.ResultsThere were 610 patients in the study (36% females). On average, women were more likely to have adenocarcinoma than were men (72% of all cases of NSCLC in women versus 40% in men; p < 0.001). In women, there was no significant relationship between FEV1 and the risk of any histological subtypes of NSCLC. In men, however, there was an inverse relationship between the risk of adenocarcinoma and FEV1 such that the lowest quartile of FEV1 was 47% less likely to have adenocarcinoma compared with the highest FEV1 quartile (adjusted odds ratio, 0.52; 0.28 to 0.98; p for trend, 0.028). The reverse was observed for squamous cell carcinoma.ConclusionIn individuals undergoing lung resection for NSCLC, the risk of adenocarcinoma and squamous cell carcinoma of the lung varies as a function of FEV1, independent of smoking intensity in men but not in women.Clinical ImplicationsThese data indicate that women are much more susceptible to adenocarcinoma than are men especially when they have normal or near normal lung function. It may thus be useful to conduct periodic surveillance chest radiographs in asymptomatic female smokers (or ex-smokers) to ascertain peripheral nodules or masses before distant metastases occur since adenocarcinomas tend to metastasize earlier in the disease course than squamous cell carcinomas.

Socio-economic status and lung cancer risk including histologic subtyping—A longitudinal study

We investigated prospectively the risk of lung cancer in relation to socio-economic status (SES) in 22,387 middle-aged individuals who attended a screening program in the city of Malmö, Sweden between 1974 and 1992. We also examined the relationship between SES and histologic subtype in smokers. By 2003, a total of 550 lung cancer cases had been identified. Relative risks (RR) were calculated with adjustment for age, current smoking, inhalation habits and marital status at baseline in the low SES group compared to high SES group. Among smokers, the RR (95% confidence interval (CI)) for lung cancer in the low SES group of men was 1.39 (1.11-1.73), and women 1.56 (1.04-2.34). Also among smokers, low SES was associated with an increased risk of squamous cell carcinoma in men; RR 1.89 (1.16-2.81) and women; RR 7.10 (1.63-30.86), and with an increased risk of mesothelioma in men RR 9.97 (1.29-76.96). We conclude that low SES groups run an increased risk of lung cancer despite accounting for smoking habits. Furthermore, low SES was positively associated with squamous cell carcinoma and mesothelioma. Our results suggest that the association between low SES and lung cancer could be mediated by unaccounted for smoking exposure, lifestyle or occupational hazards.