Occupational Exposures and Salivary Gland Cancer Mortality Among African American and White Workers in the United States

Assessing social vulnerabilities of salivary gland cancer care, prognosis, and treatment in the United States

BACKGROUND

Salivary gland cancers (SGC)-social determinants of health (SDoH) investigations are limited by narrow scopes of SGC-types and SDoH. This Social Vulnerability Index (SVI)-study hypothesized that socioeconomic status (SES) most contributed to SDoH-associated SGC-disparities.

METHODS

Retrospective cohort of 24 775 SGCs assessed SES, minority-language status (ML), household composition (HH), housing-transportation (HT), and composite-SDoH measured by the SVI via regressions with surveillance and survival length, late-staging presentation, and treatment (surgery, radio-, chemotherapy) receipt.

RESULTS

Increasing social vulnerability showed decreases in surveillance/survival; increased odds of advanced-presenting-stage (OR: 1.12, 95% CI: 1.07, 1.17), chemotherapy receipt (OR: 1.13, 95% CI: 1.03, 1.23); decreased odds of primary surgery (0.89, 0.84, 0.94), radiotherapy (0.91, 0.85, 0.97, p = 0.003) for SGCs. Trends were differentially correlated with SES, ML, HH, and HT-vulnerabilities.

CONCLUSIONS

Through quantifying SDoH-derived SGC-disparities, the SVI can guide targeted initiatives against SDoH that elicit the most detrimental associations for specific sociodemographics.

Twenty-seven years of primary salivary gland carcinoma in Wales: an analysis of histological subtype and associated risk factors

Objective

Risk factors for salivary gland carcinoma are poorly understood. Although links between background radiation, smoking and obesity have been previously suggested, no studies have so far established any significant results. This study aimed to establish correlations between common environmental and lifestyle risk factors and different subtypes of salivary gland carcinoma.

Method

A study of population data in Wales spanning 27 years was conducted; 2 national databases were used to identify 356 cases of primary salivary gland carcinoma over this period. Histological subtype of cancer and geographical location of each case was recorded. Public health data was used to establish radon levels, smoking, obesity and activity levels of populations in each geographical location. A population matched multivariate analysis of variance analysis was performed using histological subtype and risk factor data for each geographical location.

Results

A significantly higher incidence of mucoepidermoid cancer in populations with higher background radon levels (p = 0.006), epithelial-myoepithelial cancer in populations with higher smoking levels (p = 0.029) and adenoid cystic cancer in populations with higher obesity levels (p = 0.028) was found.

Conclusion

To the authors’ knowledge, this is the first study to establish significant links between background radiation, smoking and obesity with different subtypes of salivary gland carcinoma.

Major and minor salivary gland tumours

Salivary glands carcinomas are very rare epithelial malignant tumors. In 2013 in Europe, 7800 new diagnoses were estimated, 8.5 % of all head and neck cancer. The last WHO classification (2017) counts more than 20 malignant histotypes, this variety as well as the rarity of some of them needs a skilled pathologist for diagnosis. Surgery remains the mainstay of management followed by radiation in high-grade and high-risk pathological features cases. The intensity modulated radiotherapy (IMRT) should be preferred over conformational radiotherapy techniques as adjuvant and exclusive treatment in advanced cases. Particle radiotherapy (i.e. protons, carbon ions) can have a role in advanced/unresectable disease since it was proved to have better results over photons in loco-regional control both in adenoid cystic carcinoma and in other histotypes. Although chemotherapy is still the most frequent treatment for metastatic patients, several new compounds (i.e. anti-angiogenic agents, tailored agents, checkpoint inhibitors) are under investigation.

Risk factors for salivary gland cancers in France: Results from a case-control study, the ICARE study

OBJECTIVES

Epidemiological studies on the risk factors for salivary gland cancers (SGC) are rare, concern a small sample size, and show inconsistent results. The aim of the present work was to analyze several risk factors for SGC, using the data from the ICARE study, a multicenter, population-based case-control study.

MATERIALS AND METHODS

Data from 73 SGC cases and 3555 controls were collected using a standardized questionnaire on lifestyle habits, personal and family medical history, and lifetime occupational history. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regressions.

RESULTS

Tobacco use and alcohol consumption were not associated with the risk of SGC. A history of head and neck cancer or that of cervicofacial radiotherapy was associated with a higher risk of SGC (OR = 17.06, 95% CI: 4.34-67.05, and OR = 31.74, 2.48-405.25, respectively). Significantly increased risks were observed for some occupations: waiter (OR = 2.94, 1.11-7.78), charworker (OR = 3.02, 1.38-6.60), electrical and electronic equipment assembler (OR = 7.16, 2.02-25.38), plumber (OR = 3.95, 1.33-11.67), electric arc welder (OR = 6.15, 1.76-21.48), sheet-metal worker (OR = 2.89, 1.01-8.32), building painter (OR = 3.42, 1.01-11.49), and material handling equipment operator (OR = 5.05, 1.71-14.84). Results for industries were consistent with those observed for occupations.

CONCLUSION

Our results showed that a history of head and neck cancer, cervicofacial radiotherapy, and several occupations and industries, were associated with an increased risk of SGC. Further studies with larger sample sizes are indicated to confirm our results.

Racial and Ethnic Disparities in Salivary Gland Cancer Survival

IMPORTANCE

Several recent US studies have documented racial disparities in head and neck cancer outcomes, but few have investigated racial and ethnic differences in salivary gland cancer (SGCA) survival.

OBJECTIVE

To determine whether patient race or ethnicity affects SGCA survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective survival analysis of all patients with SGCA from 1988 through 2010 in the Surveillance, Epidemiology, and End Results database.

MAIN OUTCOMES AND MEASURES

Disease-specific survival according to race and ethnicity. End points assessed included age at diagnosis, sex, tumor grade, tumor size at diagnosis, extension at diagnosis, lymph node involvement at diagnosis, and treatment. Results were further analyzed by histologic subtype of SGCA.

RESULTS

Of 11,007 patients with SGCA, 1073 (9.7%) were black, and 1068 (9.7%), Hispanic. Whites' mean age at diagnosis was 63 years vs 53 and 52 years for blacks and Hispanics, respectively (P < .001). Twenty-year disease-specific survival rates for all SGCA histologic subtypes combined for whites, blacks, and Hispanics were 78%, 79%, and 81%, respectively. Unadjusted survival curves showed no significant difference between blacks and whites and an apparent advantage for Hispanics. However, multivariable Cox regression models controlling for patient, tumor, and treatment characteristics showed poorer disease-specific survival vs whites for blacks (hazard ratio [HR], 1.22 [95% CI, 1.03-1.46]; P = .03) but not for Hispanics (HR, 0.97 [0.79-1.19]; P = .77). The overall disease-specific survival disparity was due to poorer disease-specific survival for blacks vs whites with mucoepidermoid (P = .03) and squamous cell carcinomas (P = .05). Less surgical treatment for blacks than whites (57.26% vs 76.94%; P < .001) was a source of the survival disparity for squamous cell but not mucoepidermoid SGCA.

CONCLUSIONS AND RELEVANCE

Black race is a risk factor for poorer disease-specific survival for patients with mucoepidermoid or squamous cell carcinoma, whereas Hispanic ethnicity has no effect. Differing treatment between black and white patients affects survival in squamous cell but not mucoepidermoid SGCA. Differences in chemotherapy treatment, comorbidities, socioeconomic status, tumor genetic factors, and environmental exposures are potential but unproven additional sources of the racial survival disparities for mucoepidermoid and squamous cell SGCA.

Mortality from solid tumors among workers in formaldehyde industries: an update of the NCI cohort

BACKGROUND

Formaldehyde, a widely used chemical, is considered a human carcinogen.

METHODS

We extended follow-up of the largest industrial cohort of workers in formaldehyde industries (n = 25,619) by 10 years through 2004. Standardized mortality ratios (SMRs) and rate ratios (RRs) were calculated for deaths from solid tumors using quantitative formaldehyde exposure estimates.

RESULTS

During 998,239 person-years, 13,951 deaths occurred. With one additional death, previously observed excesses for nasopharyngeal cancer (n = 10) persisted for peak, average intensity and cumulative exposure; RRs in the highest exposure categories were 7.66 (95% CI: 0.94, 62.34), P-trend = 0.005, 11.54 (95% CI: 1.38, 96.81), P-trend = 0.09, and 2.94 (95% CI: 0.65, 13.28), P-trend = 0.06, respectively. For all cancer, solid tumors and lung cancer, SMRs among exposed workers were elevated, but internal analyses revealed no positive associations with formaldehyde exposure.

CONCLUSIONS

Consistent with previous analyses of this cohort, this update continues to suggest a link between formaldehyde exposure and nasopharyngeal cancer.

Mortality from solid cancers among workers in formaldehyde industries

In industrial workers, formaldehyde exposure has been associated with cancer of the nasal cavities, nasopharynx, prostate, lung, and pancreas; however, these associations are inconsistent and remain controversial. Animals exposed to formaldehyde show excesses of nasal cancer. In an extended follow-up of a large cohort of formaldehyde-exposed workers, the authors evaluated mortality from solid cancers (1,921 deaths) among 25,619 workers (865,708 person-years) employed in 10 US formaldehyde-producing or -using facilities through 1994. Exposure assessment included quantitative estimates of formaldehyde exposure. Standardized mortality ratios and relative risks were calculated. Compared with that for the US population, mortality from solid cancers was significantly lower than expected among subjects exposed and nonexposed to formaldehyde (standardized mortality ratios = 0.91 and 0.78, respectively). Relative risks for nasopharyngeal cancer (nine deaths) increased with average exposure intensity, cumulative exposure, highest peak exposure, and duration of exposure to formaldehyde (p-trend = 0.066, 0.025, <0.001, and 0.147, respectively). Formaldehyde exposure did not appear to be associated with lung (744 deaths), pancreas (93 deaths), or brain (62 deaths) cancer. Although relative risks for prostate cancer (145 deaths) were elevated for some measures of formaldehyde exposure, the trend was inconsistent. In this cohort of formaldehyde-industry workers, some evidence was found of an exposure-response relation with mortality from nasopharyngeal cancer (based on small numbers) but not for cancers of the pancreas, brain, lung, or prostate.