The incidence of breast cancer in premenopausal African American women is lower than in their white counterparts, but they are more likely to die from the disease. New findings reported in the June 7 Journal of the American Medical Association determined for the first time the population prevalence of a basal-like subtype of cancer in this group, say researchers, which may help to explain their higher mortality.
The risk of the less treatable, more deadly basal-type breast cancer was 2.1 times greater in African Americans than others: 39 percent in premenopausal African Americans, falling to 14 percent after they reached menopause. Risk for non-African American women was 16 percent, both before and after menopause.
Dr. Lisa A. Carey of the University of North Carolina at Chapel Hill and colleagues found the pattern by analyzing a subgroup of 469 women participating in the Carolina Breast Cancer Study, a population-based case-control study designed to look at molecular and environmental determinants of breast cancer risk. Study participants were sorted into two groups: those identifying themselves as African Americans and all others.
Immunohistochemical analysis of tumors was used to identify four main subtypes of breast cancer, which were then adjusted by age, race, and stage of cancer. Compared with the least threatening type, all women in the study had an 80-percent increase in mortality with the basal-like cancer. When these cases were removed from the analysis, however, younger African American women still had the highest mortality, "which may reflect the impact on prognosis of access to care, treatment, or other differences," wrote the authors.
Malignant glioma (MG), a type of brain tumor, carries a grim prognosis. Adjuvant treatment with radiation therapy and the drug temozolomide (Temodar) provides a small increase in survival; however, the disease almost always returns. A phase II study, presented at the ASCO annual meeting, of the anti-angiogenesis agent bevacizumab (Avastin) combined with irinotecan showed promising results in patients with recurrent MG.
The investigators enrolled 32 patients who had previously received radiation therapy and chemotherapy for their cancer. Four patients had thrombotic complications from the treatment regimen, but no patients developed a central nervous system hemorrhage, which had originally been a concern with the use of bevacizumab. Four patients withdrew or were removed from the study due to other toxicities, and three withdrew to have surgery for other conditions.
The overall response rate was 63 percent, and the median progression-free survival (PFS) was 24 weeks, which was greater than the PFS seen in historical control groups. The median overall survival was 40 weeks. Dr. James Vredenburgh of Duke University Medical Center, who presented the data, explained that the likely reason for the combination's efficacy was that bevacizumab suppressed abnormal tumor blood-vessel growth. This decreased the interstitial pressure around the tumor, which in turn allowed more of the cytotoxic drug to actually reach the cancer cells. The investigators now hope to test bevacizumab as an addition to first-line therapy with radiation and temozolomide for patients with newly diagnosed MG.
Computed tomography (CT) scans are an important part of surveillance for men after surgery (orchiectomy) for stage I nonseminomatous germ cell tumors (NSGCT) of the testes. Because CT scans are costly and deliver a substantial amount of radiation to the body, determining the minimum number of postoperative CT scans needed to safely follow patients has been of interest to researchers.
New data from a study presented at the ASCO annual meeting suggest that two postoperative CT scans are as safe for detecting relapse as five scans. Investigators from the United Kingdom's Medical Research Council randomly assigned 414 patients who elected to have only surveillance after surgery to follow-up routines containing either 2 CT scans (247 patients at 3 and 12 months after surgery) or 5 CT scans (167 patients at 3, 6, 9, 12, and 24 months after surgery). All other surveillance tests were performed with equal frequency between groups during monthly follow-up visits during the first year, every other month during the second year, and every 3 to 6 months thereafter.
At a median follow-up of 40 months, the investigators had detected 37 relapses (15 percent) in the 2-CT group and 33 (20 percent) in the 5-CT group. Recurrent tumors were approximately the same size at detection in both groups. "There is no clear advantage to more frequent CT scans in follow-up" of these patients, stated Dr. G.M. Mead, of the Mount Vernon Cancer Centre in Middlesex, England. "The two-CT-scan schedule can be considered a new standard."
Previous studies have suggested that risk-reducing salpingo-oophorectomy (removal of the ovaries and fallopian tubes) can prevent breast cancer in 53 to 68 percent of women who carry BRCA mutations, and prevent ovarian, fallopian tube, and peritoneal cancers in 71 to 96 percent of this group. However, these previous studies had a limited follow-up period, and did not look at whether women with BRCA1 and BRCA2 mutations derive the same benefit from risk-reducing surgery.
Data from a large prospective cohort study presented at the ASCO annual meeting suggest that women with BRCA2 mutations receive more protection from breast cancer from risk-reducing surgery than do women with BRCA1 mutations and that future studies should stratify patients by mutation type to prevent bias.
In the study, presented by Dr. Noah Kauff of Memorial Sloan-Kettering Cancer Center, 546 women who elected to undergo risk-reducing salpingo-oophorectomy (352 BRCA1 and 194 BRCA2) and 325 women who refused surgery (198 BRCA1 and 127 BRCA2) were followed for a mean of 40 months. Women with either BRCA1 or BRCA2 mutations who underwent surgery were less likely to develop gynecologic cancer and also had a lower likelihood of developing breast cancer, although the difference in breast cancer occurrence was only significant in women with BRCA2 mutations.
"There do... appear to be differences in the magnitude of protection against breast cancer conferred by risk-reducing salpingo-oophorectomy, perhaps caused by differences in the breast cancer phenotype between BRCA1 and BRCA2," stated Dr. Kauff.