Basal Cell Carcinoma Image by The National Cancer Institute via Wikimedia Commons
Abnormally frequent basal cell carcinomas (BCCs) appear to be a sign that a patient is at highly elevated risk of other cancers and should be screened more vigilantly, researchers from the Stanford University School of Medicine in Stanford, Calif., report online ahead of print in JCI Insight (Aug. 9, 2018; 3(15)).
“We discovered that people who develop six or more basal cell carcinomas during a 10-year period are about three times more likely than the general population to develop other, unrelated cancers,” said senior author Dr. Kavita Sarin, in a press release. “We’re hopeful that this finding could be a way to identify people at an increased risk for a life-threatening malignancy before those cancers develop.”
Dr. Sarin is an assistant professor of dermatology at the school of medicine.
The study was spurred by the hypothesis that frequent BCCs might be a consequence of defects in genes related to DNA repair, and whether or not such defects could also make individuals more vulnerable to other forms of cancer.
Investigators enrolled 61 patients with unusually frequent BCC development who had been seen at Stanford Hospital and Clinics from Jan. 2005 until Dec. 2015. Enrolled patients underwent germline analysis of 29 DNA repair genes.
At the same time, the authors conducted a case-control retrospective review in order to investigate any association of malignancies with frequent BCC development in a large medical insurance claims database (Truven), which included 13,264 individuals with six or more BCCs from 2007 to 2011.
“We found that about 20 per cent of the people with frequent basal cell carcinomas have a mutation in one of the genes responsible for repairing DNA damage, versus about three per cent of the general population. That’s shockingly high,” Dr. Sarin said.
As well, 21 of the 61 Stanford Hospital and Clinics patients reported a history of additional cancers, including blood cancer, melanoma, prostate cancer, breast cancer and colon cancer—a prevalence that the authors say suggests the frequent basal cell carcinoma patients are three times more likely than the general population to develop cancers.
The 13,264 individuals in the Truven database who had six or more BCCs were also more than three times as likely to have developed other cancers, including colon, melanoma and blood cancers.
Overall the researchers identified an upward trend, where the more BCCs an individual reported, the more likely that person was to have had other cancers as well.
“I was surprised to see such a strong correlation,” Dr. Sarin said. “But it’s also very gratifying. Now we can ask patients with repeated basal cell carcinomas whether they have family members with other types of cancers, and perhaps suggest that they consider genetic testing and increased screening.”