More than 30,000 medical professionals from around the world who treat people with cancer will meet later this month in Chicago at the 2008 American Society of Clinical Oncology (ASCO) Annual Meeting to discuss the latest advances in cancer care, treatment, prevention, and survivorship. As of today, nearly 5,000 studies are available online, and several of these are highlighted below. To learn more about the results of these studies, and what they mean for people with cancer, Cancer.Net talked with Julie Gralow, MD. Cancer.Net will feature more news from late-breaking studies presented at the meeting on May 30 to June 2.

Q: One lung cancer study showed that additional chemotherapy delayed the cancer's growth. How will this affect the care of patients with lung cancer?

A: In this study, patients with advanced stage non-small cell lung cancer were included if they had already received four cycles of chemotherapy (including platinum-based drugs) and if their cancer had not progressed (continued to grow). They were then randomized to receive another chemotherapy, pemetrexed (Alimta), or a placebo (an inactive drug), which continued until the cancer progressed. The group that received pemetrexed had a longer time until the cancer started to progress, and they also had higher tumor response rates (shrinkage) compared with the patients who received the placebo. The severity of side effects was not majorly different between the two groups. Prior to this study, the use of "maintenance" therapy after the first chemotherapy was completed was not proven to be of value - additional chemotherapy was not started until clear signs of cancer regrowth. This study suggests that patients with advanced lung cancer may benefit from "maintenance" chemotherapy, given after their first chemotherapy regimen and before the tumor begins to regrow.

Q: Another lung cancer study identified a "gene expression signature" that may help identify which patients will benefit most from chemotherapy after surgery. What is the significance of this study, and what is meant by a "gene expression signature?"

A: A "gene expression signature" is a laboratory analysis of which genes are turned up or down in a cancer cell compared with normal cells. This particular signature was designed to help identify which patients with early-stage lung cancer are at high risk for cancer recurrence (return of the cancer) and death, and which aren't, with the goal of potentially avoiding chemotherapy in patients who are likely to do well without it. Genes in this signature play a role in cancer cell growth or death. The researchers in this study tested a panel of 15 genes in tumor samples from patients with early-stage lung cancer who had been part of an earlier clinical trial in which they had been randomized to receive chemotherapy or no chemotherapy. These overall results showed a benefit for giving chemotherapy. This gene signature was able to separate patients into those with a high risk of death due to cancer, and those with a low risk. Additionally, those with a high risk benefited from chemotherapy (it decreased their risk of death), but those with low risk did not. These preliminary findings suggest that we may be able to identify patients with less aggressive (low-risk) cancers and spare them the side effects of chemotherapy.

Q: What are researchers learning about women with vitamin D deficiency at the time of breast cancer diagnosis, and how could this finding affect patients?

A: There is an emerging body of data linking vitamin D deficiency to a variety of health problems, including an increased risk of some cancers. A group of researchers from Canada tested vitamin D levels in newly diagnosed patients with breast cancer. About three-quarters of them had low levels of vitamin D at diagnosis. After following them for 10 years, they report that patients with vitamin D deficiency were more likely to experience cancer recurrence and death compared with women with normal levels of vitamin D at diagnosis. This is potentially a very important finding for patients with breast cancer. Future studies will need to address whether correcting low levels of vitamin D at diagnosis can improve long-term outcome for breast cancer.

Q: Please discuss some of the research surrounding the choices women with early-stage breast cancer are making to have a mastectomy (removal of a breast) instead of a lumpectomy (removal of the tumor and a small amount of surrounding tissue).

A: Clinical trials with over two decades of follow-up demonstrated that overall survival rates were equal for patients with early-stage breast cancer who underwent mastectomy versus lumpectomy plus radiation therapy. Deaths were equal in these clinical trials for the two surgical approaches, which encouraged us to recommend less aggressive surgery in the majority of patients with early-stage breast cancer. The group who underwent lumpectomy did have about a 10% local recurrence rate in the breast (which was generally treated at the time of recurrence with mastectomy), even with the addition of radiation. In the 1990s, we saw an increase in lumpectomy as the choice of surgery for patients with early-stage breast cancer, while mastectomies decreased. Several groups have recently reported that mastectomy rates are on the rise in the United States and it is not clear why this is happening. A group at the Mayo Clinic report that the use of breast magnetic resonance imaging (MRI) at the time of breast cancer diagnosis has been increasing between 2003 and 2006 and that women who undergo breast MRI have higher rates of mastectomy. It is possible that MRI may contribute to the increase in mastectomy because it better detects additional findings in the breast, which might make mastectomy a more appropriate treatment option if those findings are cancerous. But if those MRI findings are not cancerous, the choice of mastectomy may be an unnecessarily and overly aggressive surgery. We still have a way to go in determining the role of breast MRI at the time of breast cancer diagnosis. Other factors that may contribute to a woman's choice of mastectomy versus lumpectomy include the increasing use of genetic testing, which can define a group of women at very high risk of subsequent breast cancers, a woman's personal preference for reducing possible future biopsies and recurrences, and the improved methods for breast reconstruction now available.

Q: One study found that survivors of childhood cancer are 5 to 10 times more likely than their healthy siblings to develop heart disease in early adulthood. What does this mean for these survivors?

A: While it is terrific news that more and more childhood cancer patients are surviving into adulthood, we cannot ignore the long-term consequences and impact of their treatment. This study observed that survivors of childhood cancer were 5 to 10 times more likely to develop heart disease as young adults compared with their brothers and sisters. This study reinforces the role of long-term follow-up care of cancer survivors, and in childhood cancer survivors the need for individualized heart screening and clinical trials of interventions and strategies to reduce the risk of early heart disease.

Dr. Gralow is Associate Professor of Medicine/Oncology at the University of Washington School of Medicine and Fred Hutchinson Cancer Research Center in Seattle. She is Chair of ASCO's Cancer Communications Committee.

More Information

To learn about late-breaking cancer studies presented at the 2008 ASCO Annual Meeting, visit Cancer.Net: ASCO Annual Meetings on May 30 to June 2.