THE EPIDEMIOLOGY OF LIP, ORAL, AND PHARYNGEAL CANCERS, AND THE ASSOCIATION WITH SELECTED SYSTEMIC DISEASES

Sore or Swollen Lips Part 2: Systemic Causes

This series of three papers reviews the causes, diagnosis and differential diagnosis, and outlines the management of sore and/or swollen lips. Clinical relevance: Sore and/or swollen lips are not uncommon, often have a local cause, but may reflect a systemic disease. The previous article reviewed important causes, from actinic to contact cheilitis, while this paper starts with drug-induced cheilitis and completes that alphabetical list.

Solar radiation, lip protection, and lip cancer risk in Los Angeles County women (California, United States)

A population-based case-control study of 74 women with lip cancer diagnosed from 1978 to 1985 in Los Angeles County (California, United States) and frequency matched to 105 controls investigated the risk of solar radiation and protection from lip sunscreening agents to explore the hypothesis that excess incidence of lip cancer seen in men is due partly to lower rates in women, conferred by frequent use of lip protection. We confirm the importance in women of risk factors similar to those found in men, i.e., fair complexion, sun exposure, and smoking. Risk was related strongly to lifetime solar radiation (odds ratio [OR] = 13.5 for highest quartile of exposure, 95 percent confidence interval [CI] = 4.5-40.6, P trend < 0.0001) and time spent outdoors (OR = 4.7 for highest quartile of average yearly hours, CI = 1.9-12.1, P trend = 0.01). Further, among women with high lifetime solar-radiation exposure, those who used lip protection once a day or less had twice the risk of lip cancer than women who used lip protection more than once a day (OR = 7.3, CI = 1.9-27.2 cf OR = 3.2, CI = 1.1-9.2). These findings show that solar radiation is a major risk factor for lip cancer and suggest that lip sunscreening is protective, thereby supporting the hypothesis that use of lipstick and other sunscreening agents by women has contributed to their lower incidence of this disease.

Cutaneous manifestations and consequences of smoking

Cigarette smoking is strongly linked to serious internal diseases such as cancer, cardiovascular disease, and lung disease. However, the external manifestations and consequences of smoking are relatively unknown. Although generally less ominous, the cutaneous manifestations of smoking may be associated with significant morbidity. This article reviews the known adverse effects on the skin of smoking.

Actinic cheilitis: a review of the etiology, differential diagnosis, and treatment

With today's increase in sun worshippers, the number of sun-induced skin lesions is increasing. Actinic cheilitis is the counterpart of actinic keratosis of the skin and can also develop into squamous cell carcinoma. In this article we review the etiology, clinical spectrum, histology, differential diagnosis, and treatment of actinic cheilitis. Actinic cheilitis needs to be differentiated from many other lip conditions, and the dermatologist must be attune to its possibility whenever assessing scaly lips. Because of its potential to develop into squamous cell carcinoma, treatment should be instituted as soon as possible.

Reassessing the epidemiology of lip cancer

The risk factors associated with carcinoma of the lip are reviewed with an aim toward reassessing the epidemiology of the disease. Descriptive studies show lip cancer to occur most commonly in aging white men. The geographic distribution of the disease varies widely, both nationally and internationally; recent studies show that at the national level there is not a uniformly high risk of lip cancer across the sunny states, as has been believed. Secular disease trends show a decline in both morbidity and mortality while survival rates have remained stable. The risk factors consistently associated with lip cancer are rural residence and outdoor occupation, but the latter does not apply to all outdoor workers. In addition, both actinic radiation and tobacco smoking have long been considered to be causally related to lip cancer. An extensive review of the literature, however, reveals that the studies evaluating the association between these exposure variables and the disease do not yield consistent results; in addition, many recent, well-designed studies fail to support independent causal hypotheses. We conclude that (1) any risk factors considered to be causally related to lip cancer must be congruent with the descriptive factors (geographic distribution, secular disease trends, etc.) and (2) although sunlight and smoking are highly likely risk factors, their interrelationship as well as their interaction with other factors, such as genetic predisposition, needs reassessment.

Occupations with low risk of lip cancer show high risk of skin cancer of the head

The standardized morbidity ratios (SMR) of lip and non-melanomatous skin cancer (basal-cell carcinoma excluded) of the head and neck in males were determined for different occupational groups in Finland. The data on all cases of these types of cancer diagnosed in Finland in the age group 35-69 years in 1971-75 were supplemented by information on occupations from the 1970 census (Central Statistical Office of Finland). The expected numbers of cases were based on the age and occupation-specific numbers of person-years computed by the Central Statistical Office, and the age-specific incidence rates of lip and skin cancers among the economically active population. The highest SMR of lip cancer among all the occupational groups was found in agriculture, forestry and fishing (1.64). In contrast, the SMR of skin cancer was not higher than expected in occupations related to agriculture and forestry. Significantly lower than expected risks of lip cancer were observed among highly educated white-collar workers, among whom the risk of contracting skin cancer was the highest (technical, scientific, humanistic and artistic work, SMR 1.78). The morbidity of both lip and skin cancers varies considerably by occupation, and the risks seem to be, at least in part, inversely related. Thus, it is probable that there are also differences in the risk factors, contrary to several earlier suggestions. The nature of these factors are discussed.

Epidemiological evaluation of sunlight as a risk factor of lip cancer

A total of 3,169 cases of lip cancer in males and 303 cases in females were diagnosed in Finland and reported to the Finnish Cancer Registry in 1953-73. The diagnosis was verified histologically in 95% of the cases in males and in 92% in females. The mean annual age-adjusted incidence rate was 7·3/10(5) in males and 0·5/10(5) in females. The annual incidence for males has decreased since the early 1960s. The decrease involved all age groups and was not due to a cohort effect. Only a very slight decrease in the risk was observable in females. The incidence was clearly higher in rural than in urban areas, the urban/rural ratio of the age-adjusted incidence rates being 0·6 for males. A decrease in the risk with time was observable for both urban and rural populations. The risk was highest in the northern and eastern parts of the country, for both urban and rural areas. It was concluded that the decrease in the incidence of lip cancer in Finland cannot be accounted for solely by the process of urbanization. An inverse relationship was found between the mean annual amount of solar radiation and the risk of lip cancer. The results are not in accordance with the theory of the association between exposure to actinic radiation and the risk of lip cancer. The synergistic action of some other factors related to outdoor occupation, and probably smoking, would provide a better explanation for the observations in this study.

Squamous-cell carcinoma of the floor of the mouth

This study was based on the analysis of 100 cases of squamous-cell carcinoma of the floor of the mouth. The male/female ratio was 4.25:1. The peak incidence in women was in the 50 to 59 year age group; in men there was equal frequency in each age group above 50. The five-year survival rate decreased from 86 per cent to 0 as the stage of disease progressed from I to IV. The five-year survival for all stages of disease was 52.7 per cent. Thirty-three per cent developed new primary malignancies; 22 per cent were of the upper alimentary and respiratory tracts. Distant metastases were present in 21 per cent. Fifty per cent were heavy smokers, 33 per cent were heavy drinkers, 28 per cent were both heavy smokers and heavy drinkers, and 21 per cent were nonsmokers and nondrinkers.

Oral cancer in Puerto Rico

All cancer cases diagnosed in Puerto Rico are analyzed and registered in the Central Cancer Registry. The incidence of oral cancer in Puerto Rico is fourth-highest in the world. (In 1972 oral cancer accounted 72% of all cancers in males in Puerto Rico.) A review of the data revealed important contrasts with reported statistics from the continental United States (e.g., 75.6% of the cases in Puerto Rico were initially treated by radiation, compared with 15.3% of the cases in Western New York States.

The occupation of fishing as a risk factor in cancer of the lip

To study the role of commercial fishing and related factors in the development of lip cancer, a project that included a case-control study and a cohort analysis was undertaken in Newfoundland. Household survey data were linked with cancer-registry and census data. In comparison with other males, fishermen had a probability of development of lip cancer that was 1.5 times higher (by the case-control method, P less than 0.05) or 4.4 times higher (by cohort analysis, P less than 0.001). Despite the effect of pipe smoking, "outdoorness" and age on the development of lip cancer in general, the occupation of fishing was an additional, independent contribution to the risk. Unexpectedly, using the mouth as a third hand to handle tar-coated nets seemed to protect fishermen from the disease. It was not possible to attribute the higher risk to a particular work activity, nor was a specific responsible carcinogen identified.