The risk profiles for individuals who develop single vs. multiple basal cell carcinoma lesions differ, according to findings from the Rotterdam Study.
Of the 10,820 eligible members of the two cohorts used for the large, Dutch, population-based study, 361 (3%) were diagnosed with a single initial basal cell carcinoma (BCC) lesion, and 163 (1.5%) were diagnosed with subsequent BCC lesions during the study period.
After adjusting for numerous factors such as sex, age, hair and eye color, tendency to develop sunburn, smoking history, body mass index, and educational level, factors found to be significantly associated with developing a first BCC lesion were age (odds ratios of 1.39 and 1.01 for those aged 65-74 years and for those aged 75 years and older, respectively, vs. those younger than age 65 years), and red hair color (OR of 1.98 for red vs. brown or black hair), Dr. Ville Kiiski and colleagues at Erasmus Medical Center, Rotterdam, the Netherlands, reported in the August issue of Archives of Dermatology.
After adjusting for age at index lesion, sex, hair color, eye color, all ultraviolet-related factors, smoking history, and alcohol consumption, the factors found to be associated with a significantly increased risk of developing multiple lesions were lesion location on an upper extremity (hazard ratio 1.49), age younger than 65 years (HRs of 0.58 and 0.65 for those aged 75 years and older and for those aged 65 to 74 years, respectively, vs. those younger than age 65 years), hair color (HR of 1.43 for red vs. brown/black hair), and education level (HR of 1.42 for high vs. low education level), the investigators found (Arch. Dermatol. 2010;146:848-55).
This last finding “may be explained by the probability that people with higher levels of education (which correlates strongly with socioeconomic status) have different lifestyles,” such as more frequent exposure to ultraviolet rays for intermittent periods, they said. Also, people of higher socioeconomic status generally may be expected to live longer and, thus have more time to acquire lesions.
Patients were adults aged 55 years or older from the two Rotterdam Study cohorts, including one studied in 1990, and one studied in 1999. Participants were followed for a mean of 9.5 years.
The findings – particularly regarding increased risk among younger patients and red-heads – largely support those of previous studies, although in the current study men were not shown to be at significantly increased risk of developing a first lesion, which contrasts with findings from some prior studies, the investigators noted.
The differences in risk factor profiles for those who develop single vs. multiple BCC lesions, as seen in the current study, may suggest that phenotypic characteristics of patients are less important for determining risk once “cumulative environmental-genetic interaction has surpassed a certain threshold and resulted in a lesion,” Dr. Ville Kiiski and colleagues wrote.
“The clinical relevance of this finding is that physicians’ risk assessment efforts should differentiate between patients at risk for a first lesion and those who have a history of BCC,” they said, noting that those with the identified risk factors for multiple lesions may require a more stringent follow-up regimen.
That’s not to say, however, that other BCC patients do not require follow-up. In this sample of the general population, more than 30% of the patients with BCC developed subsequent skin cancer, emphasizing the need for annual follow-up for several years,” Dr. Ville Kiiski and colleagues stressed.
Given that more than 1 million people are diagnosed with BCC in the United States each year, and given the strain that is put on limited specialized care by the need for follow-up of the large group of patients with BCCs, additional research is needed to better identify those at risk of developing multiple lesions, they concluded.
The investigators reported no financial disclosures relevant to their study.