2013 American Association for Cancer Research meeting

Excessive ovulation tied to cancer risk
Women who undergo many ovulatory cycles in a lifetime might be at increased risk of ovarian cancer, an analysis has found. The “incessant ovulation” hypothesis, which scientists proposed decades ago, holds that undergoing many cycles might increase cancer risk through high estrogen levels, more mutations in cells that line the ovaries or more shedding and regrowth of the uterine lining. But the hypothesis remains controversial. Epidemiologist Hannah Yang of the National Cancer Institute and her colleagues analyzed data  on the number of ovulatory cycles in nearly 800 women in Warsaw and Lodz, Poland, from 2001 to 2003. Cycle numbers were estimated by assessing age at first period, age at menopause, total time pregnant, duration of breastfeeding, use of oral contraceptives and other factors. The women had roughly 200 to 600 ovulatory cycles in a lifetime, Yang said. When she and her colleagues divided the women into four equal groups by number of cycles, those in the quarter with the most cycles were two to three times as likely to develop ovarian cancer as were those who had the fewest ovulatory cycles. The number of cycles wasn’t linked to uterine cancer risk, Yang reported April 7. — Nathan Seppa

Breast cancer patients do better on statins
Cholesterol-lowering drugs might limit the lethality of breast cancer. While these drugs, called statins, can kill breast cancer cells in laboratory tests (SN: 5/5/2012, p. 30), scientists don’t know whether they can prevent the disease in people or help breast cancer patients. Teemu Murtola, a physician and epidemiologist at Johns Hopkins University and colleagues analyzed records of more than 31,000 women in Finland who received a first-time diagnosis of breast cancer from 1995 to 2003. Among women diagnosed with localized breast cancer, those who began taking statins afterward were one-third as likely to die from the cancer by the end of 2003 as those not getting the drugs, Murtola reported April 7. Among women whose breast cancer had already spread to other organs by the time of diagnosis, those who subsequently took statins were half as likely to die from the cancer as those not getting the drugs. Having taken statins before diagnosis also showed some protection, but mainly for women on a high dose. The most common statin women took was simvastatin (Zocor), followed by atorvastatin (Lipitor). — Nathan Seppa

New drug candidate tackles chronic leukemia
A little-tested drug candidate has shown promise against chronic lymphocytic leukemia, the second-most common leukemia in adults. CLL is a slow-growing cancer in which many blood stem cells fail to become normal white blood cells, including immune system soldiers called B cells. The experimental drug, called ibrutinib, inhibits an enzyme that plays a central role in B cells that are in the throes of turning cancerous. Adrian Wiestner, a hematologist and researcher at the National Heart, Lung and Blood Institute and his colleagues gave ibrutinib to 53 CLL patients. Some patients had never been treated and some had failed to improve on other drugs. After six months, the patients on average had reduced swelling of the spleen, a good sign. Other measures showed that the drug controlled the malignancy in blood, bone marrow and lymph nodes. Notably, the researchers found a sharp reduction in the number of cancerous cells in the blood stream making a protein called Ki-67, a well-known sign of proliferation in CLL, Wiestner reported April 8. — Nathan Seppa

Breast cancer mortality higher among black women
Black women with breast cancer are more likely to die from the disease than are women of other races with breast cancer, new research suggests. The disparity exists regardless of type of breast cancer the women had. For the study, epidemiologist Candyce Kroenke of Kaiser Permanente in Oakland, Calif., and colleagues looked at data on four breast cancer subtypes in nearly 1,700 breast cancer survivors from four different races. After six years, 500 of the women had died, 268 of them from breast cancer. Across all four cancer subtypes, a higher fraction of black women died —23 percent — than of women of other races, Kroenke reported April 6. Compared with white women, black women were 1.3 to 2.6 times as likely to die of the disease, depending on their cancer subtype. Those ratios held true even after controlling for socioeconomic status and lifestyle factors such as smoking, she says. Researchers previously thought that black women were at higher risk of death because they are more likely to get the deadliest subtypes of the disease. Although Kroenke and colleagues did find that black women got the deadliest subtypes more often, that difference didn’t entirely explain their higher death rate, she says. More research could tease out potential explanations for the differences, such as treatment choices, pollution exposure, stress and genetics, she says. — Puneet Kollipara