Women are being significantly undertreated for head and neck cancer, according to the results of a study (abstract LBA6002) presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 1–5. An analysis of a cancer registry in California has found that women with head and neck cancer were less likely to receive intensive chemotherapy and radiation, compared with men.
“We weren’t looking for gender differences, so the results were really surprising,” said senior study author Jed A. Katzel, MD, a medical oncologist at Kaiser Permanente in Santa Clara, California.
The researchers evaluated health outcomes for 223 female and 661 male patients with stages II–IVB head and neck cancer treated at Kaiser Permanente Northern California. The odds of receiving intensive cancer treatment were estimated using logistic regression models. The researchers also adjusted for factors such as age, gender, tumor stage, Charlson Comorbidity Index, and history of smoking and alcohol use.
The team used a mathematical tool, the generalized competing event (GCE) model, to compare the risk of dying from cancer to the risk of dying from other causes. The GCE model controls for differences in age, gender, tumor site, and Charlson score. The researchers found that the odds of receiving intensive chemotherapy were 35% for women vs 46% for men, and the odds of receiving radiation were 60% for women and 70% for men.
At a median follow-up of 2.9 years, 271 patients had died of cancer and 93 died from other causes. While both men and women were more likely to die of cancer than of other causes, the ratio of cancer deaths vs noncancer deaths was 1.92 times higher for women than for men.
While further analysis is ongoing, one of the factors that must be considered is that the researchers did not control for differences in tumor type with respect to HPV status. HPV-related head and neck tumors are more responsive to treatment, and patients with such cancers generally have a better prognosis. HPV-related head and neck cancer is more common in men than in women. In the authors’ prior analysis of patients in Northern California, they found that only about 22.6% of HPV-related cancers occurred in women, compared with 77.4% in men.
“Besides undertreatment, there are a number of factors that could contribute to the differences in outcomes between women and men with head and neck cancer, and it’s clear we need further investigation,” said Dr. Katzel.
Commenting on the study, ASCO Expert Joshua A. Jones, MD, from Perelman School of Medicine at the University of Pennsylvania, Philadelphia, said it is unknown if what is occurring in California reflects what is happening elsewhere in the United States. “Though these findings are specific to California, the disparities we see are startling and worth considering in treatment discussions in everyday practice,” Dr. Jones said. “We don’t know why women are getting less treatment and having worse outcomes, and we need to find out.”