New research was presented at the 2012 American Society of Clinical Oncology annual meeting from June 1-5, 2012 in Chicago. The features below highlight just some of the studies that emerged from the conference.
Examining Awareness of Late Effects of Cancer Treatment
The Particulars: The population of cancer survivors continues to grow, but with it has come a growing number of patients who may experience the late or long-term effects (LEs) of treatment. Awareness on the part of oncologists and primary care providers (PCPs) of these LEs is not well understood.
Data Breakdown: A nationally representative survey of oncologists and PCPs asked respondents to report the five LEs they had observed and/or seen reported in the literature for each of four standard chemotherapy agents for breast or colorectal cancer treatment. About one-third (65%) of oncologists identified the main LEs for all four chemotherapy drugs, but only 6% of PCPs accomplished the same feat. Oncologists were more likely to identify the main LEs if they spent 51% to 90% (odds ratio [OR], 1.87) or more than 90% (OR, 1.82) of their time on patient care. They were less likely to do so if they were not board certified.
Take Home Pearls: Oncologists appear to often identify the main LEs of cancer treatment, while PCPs do not. Findings emphasize the importance of informing PCPs of the LEs of cancer treatments during patient transitions from oncology to primary care settings.
Low-Dose Radiation Beneficial With CNS Lymphoma
The Particulars: For many years, whole-brain radiation has been used to treat central nervous system (CNS) lymphoma, but this treatment has been associated with relatively poor outcomes. Additionally, surgery is usually not an option. Studies have suggested that combining radiation and chemotherapy can improve outcomes but increase neurotoxicity. Whole-brain radiation at about half the standard dose after chemotherapy to treat CNS lymphoma may be effective while limiting toxicity.
Data Breakdown: Researchers treated 52 patients with newly diagnosed CNS lymphoma with a chemotherapy regimen followed by either wholebrain radiation at 23.4 Gy or 45.0 Gy. The average progression-free survival (PFS) for those who received the reduced dose of radiation was nearly 7.7 years. The 2-year PFS was 78%. In the intentto- treat group, median PFS was 3.3 years and the median overall survival was 6.6 years. Cognitive testing after chemotherapy demonstrated significant improvements in executive function and verbal memory that were stable over the follow-up.
Take Home Pearl: For patients with CNS lymphoma, whole-brain radiation at about half the standard dose following chemotherapy appears to be safe and effective.
Chest Radiation for Childhood Cancers Linked to Later Breast Cancer
The Particulars: Research has shown that intensive radiation for Hodgkin’s lymphoma during childhood appears to increase breast cancer risk. However, how intensive radiation during childhood compares with other risk factors (eg, certain mutations) remains less clear. The effects of lower doses of radiation for other childhood cancers are also unknown.
Data Breakdown: In a study, data on the cumulative incidence of breast cancer after radiation therapy from 5-year cancer survivors and first-degree female relatives of women carrying the BRCA1 and BRCA2 mutations were analyzed. For women exposed to 20 Gy or more radiation to treat Hodgkin’s lymphoma, the cumulative incidence of breast cancer at age 50 was 31%, which was comparable to the 30% rate seen in relatives of carriers of the BRCA1 mutation. Those exposed to 10 Gy to 19 Gy or whole-lung radiation had a 10% rate, which was comparable to that seen in relatives of carriers of the BRCA2 mutation.
Take Home Pearls: Females treated with chest radiation for childhood cancers appear to have an elevated breast cancer risk, even at low doses of radiation. The cumulative incidence of breast cancer for those who received radiation at 20 Gy or more appears to be comparable to relatives of carriers of the BRCA1/2 mutation.
Mutations Predict Benefits in Brain Tumor Treatment
The Particulars: Since the early 1990s, the standard of care for anaplastic oligodendroglial brain tumors has been surgery followed by radiotherapy. Research has shown little benefit from the addition of chemotherapy in this patient population. Studies, however, suggest that some of these patients may benefit from the addition of chemotherapy.
Data Breakdown: Researchers randomized patients with newly diagnosed, previously untreated anaplastic oligodendroglioma or oligoastrocytoma to radiation therapy alone or followed by six cycles of chemotherapy. Patients who received radiation plus chemotherapy had a 44% lower risk of death and an average overall survival gain of 28 months when compared with radiation-only recipients. These differences were almost entirely accounted for by patients with specific genetic deletions in chromosomes 1 and 19.
Take Home Pearl: In patients with anaplastic oligodendrogail brain tumors, those with genetic deletions in chromosomes 1 and 19 may benefit with the addition of chemotherapy to radiation.
Age Matters in ALL Outcomes
The Particulars: Previous investigations have suggested that adolescents and young adults with acute lymphoblastic leukemia (ALL) have worse long-term outcomes than children with the disease. However, the magnitude of this observed difference has not been well studied among larger groups of older adolescents and young adults with ALL.
Data Breakdown: An analysis compared the outcomes of patients with ALL aged 16 to 30 with those with ALL who were younger. The risk of relapse was significantly higher for older patients (21.3%) when compared with the younger cohort (13.4%). Rates of bone marrow relapse and death during remission were 15.3% and 5.5%, respectively, for older patients, compared with 9.0% and 2.1%, respectively, for younger patients.
Take Home Pearl: Older adolescents and young adults with high-risk ALL appear to experience worse outcomes relating to the disease than children with ALL.
Readings & Resources (click to view)
For more information on these studies and others that were presented at the 2012 American Society of Clinical Oncology annual meeting, go to http://chicago2012.asco.org.