Mechanisms of Immune Tolerance in Leukemia and Lymphoma.

The mechanisms through which immune responses are generated against solid cancers are well characterized and knowledge of the immune evasion pathways exploited by these malignancies has grown considerably. However, for hematological cancers, which develop and disseminate quite differently than solid tumors, the pathways that regulate immune activation or tolerance are less clear. Growing evidence suggests that, while numerous immune escape pathways are shared between hematological and solid malignancies, several unique pathways are exploited by leukemia and lymphoma. Below we discuss immune evasion mechanisms in leukemia and lymphoma, highlighting key differences from solid tumors. A more complete characterization of the mechanisms of immune tolerance in hematological malignancies is critical to inform the development of future immunotherapeutic approaches.

Do children and adults differ in survival from medulloblastoma? A study from the SEER registry.

Studies investigating whether adults have diminished survival from medulloblastoma (MB) compared with children have yielded conflicting results. We sought to determine in a population-based registry whether adults and children with MB differ in survival, and to examine whether dissimilar use of chemotherapy might contribute to any disparity. 1,226 MB subjects were identified using the Surveillance Epidemiology and End Results (SEER-9) registry (1973-2002) and survival analysis performed. MB was defined strictly to exclude non-cerebellar primitive neuro-ectodermal tumors. Patients were stratified by age at diagnosis: <3 years (infants), 3-17 years (children) and >or=18 years (adults). Because the SEER-9 registry lacks treatment data, a subset of 142 patients were identified using the San Francisco-Oakland SEER registry (1988-2003) and additional analyses performed. There was no significant difference in survival between children and adults with MB in either the SEER-9 (P = 0.17) or SFO (P = 0.89) cohorts but infants fared worse compared to both children (P < 0.01) and adults (P < 0.01). In the SFO sample, children and adults who received chemotherapy plus radiation therapy (XRT) did not differ in survival. Among patients treated with XRT alone, children showed increased survival (P = 0.04) compared with adults. Children and adults with MB do not differ with respect to overall survival, yet infants fare significantly worse. For children and adults with MB treated with both XRT and chemotherapy, we could not demonstrate a survival difference. Similar outcomes between adult and childhood MB may justify inclusion of adults in pediatric cooperative trials for MB.

Gender affects survival for medulloblastoma only in older children and adults: a study from the Surveillance Epidemiology and End Results Registry.

BACKGROUND: Males have a higher incidence of medulloblastoma (MB) than females, but the effect of gender on survival is unclear. Studies have yielded conflicting results, possibly due to small sample sizes or differences in how researchers defined MB. We aimed to determine the effect of gender on survival in MB using a large data set and strict criteria for defining MB. PROCEDURE: A sample of 1,226 subjects (763 males and 463 females) was identified from 1973 to 2002, using the Surveillance Epidemiology and End Results (SEER-9) registry. MB was strictly defined to exclude non-cerebellar embryonal tumors (primitive neuro-ectodermal tumors). Because children <3 years of age are known to have worse survival, patients were stratified by age <3 years at diagnosis (95 males, 82 females) and >3 years (668 males, 381 females). RESULTS: Overall, there was no significant difference in survival between males and females (log rank P = 0.22). However, among subjects >3 years, females had significantly greater survival than males (log rank P = 0.02). In children <3 years, there was a non-significant trend toward poorer survival in females (median survival: males 27 months, females 13 months; log rank P = 0.24). This interaction between age group and gender was statistically significant (P = 0.03). CONCLUSION: Females with MB have a survival advantage only in subjects >3 years. In children <3 years, females may even have poorer outcome. The effect of gender on survival and incidence in MB warrants additional biologic investigation, and may differ in very young children with MB.

Medulloblastoma incidence has not changed over time: a CBTRUS study.

Earlier studies have reported changes in the incidence of medulloblastoma (MB) but have conflicted, likely because of small sample size or misclassification of MB with primitive neuroectodermal tumor (PNET). The incidence of MB and PNET from 1985 to 2002 was determined from the Central Brain Tumor Registry of the United States, a large population-based cancer registry, using strict histologic and site codes. No statistically significant change in MB incidence was observed over the last 2 decades, but there was an increase in MB and PNET combined.

Survival and selected outcomes of older adults with locally advanced head/neck cancer treated with chemoradiation therapy.

OBJECTIVES: Chemoradiation therapy (CRT) remains a potentially curative treatment in patients with locally advanced head/neck cancer (LA-HNC). However, survival and other outcomes in older patients with head/neck cancer receiving chemoradiotherapy are not well established. This study was performed to elucidate selected outcomes in this patient population. MATERIALS AND METHODS: Retrospective study of LA-HNC patients ≥ 70 years of age who had received 5-fluorouracil-hydoxyurea-based CRT with a minimum of 3 years of follow up after therapy initiation was performed. Pre-treatment patient- and cancer-related characteristics were recorded. Survival data in addition to gastrostomy tube utilization, swallowing function, and hematologic toxicity were captured. RESULTS: Eighty-nine patients treated between 1997 and 2009 were eligible for analysis (median age, 76 years; range, 70-94; male, 61%; ECOG PS, 0-1 43%; stage IVA/B, 71%). 86 were evaluable for survival analysis. 5-year overall and event-free survival were both at 32% with a median follow-up time of 39.2 months. The majority (86.5%) were able to complete all planned treatment cycles. A significant proportion of patients, however, required gastrostomy tube during CRT (62%) and developed aspiration during swallowing evaluation post-treatment (44%). Several patients required hospice (9%) or skilled nursing facility (13%) referrals during treatment. CONCLUSION: Select older adults with LA-HNC can still experience long-term benefits despite 5-year survival rates lower than those historically reported in younger patients undergoing identical CRT regimens although potentially at higher risk for acute toxicities. Assessment and selection of those who can tolerate more intense combined-modality strategies and their long-term outcomes merit further larger, prospective studies.