Objectives: Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin cancer with higher incidence among whites, elderly, and immunosuppressed patients. Although immunosuppressed MCC patients are at higher risk of recurrence and MCC-related death, it is unknown whether immunosuppression type is associated with differential outcomes. Materials and Methods: We retrospectively evaluated 89 nonmetastatic MCC patients with a diagnosis of chronic immunosuppression. Immunosuppression was categorized as chronic lymphocytic leukemia (31% of cohort), other hematologic malignancies (18%), solid organ transplant (21%), autoimmune disease (21%), and human immunodeficiency virus acquired deficiency syndrome (8%). Progression-free survival (PFS) and MCC-specific survival (MSS) were estimated with the cumulative incidence function. Overall survival (OS) was estimated by the Kaplan-Meier method. Results: With a median follow-up of 52 months, 53 deaths occurred (42 from MCC, 7 unknown, and 4 non-MCC). Two-year PFS, MSS, and OS were 30%, 55%, and 52%, respectively. Human immunodeficiency virus/acquired deficiency syndrome and solid organ transplant patients were diagnosed with MCC at a younger age (median 55 and 59 y, respectively) and with more advanced stage disease compared with other immunosuppressed subgroups. PFS did not significantly differ among the 5 immunosuppression subgroups (P=0.30), but significant differences were observed in MSS and OS (both P=0.01). Controlling for potential confounders for OS, including age and stage, immunosuppression type was still significantly associated with risk of death (P=0.01). Conclusions: Among immunosuppressed MCC patients, recurrent MCC is the major cause of mortality. The risk of death from MCC differs among immunosuppression types, suggesting important biological differences in host-tumor immune interactions.

Background: Existing pencil beam analytical (PBA) algorithms for proton therapy treatment planning are not ideal for sites with heterogeneous tissue density and do not account for the spatial variations in proton relative biological effectiveness (vRBE). Using a commercially available Monte Carlo (MC) treatment planning system, we compared various dosimetric endpoints between proton PBA, proton MC, and photon treatment plans among patients with mediastinal lymphoma. Methods: Eight mediastinal lymphoma patients with both free breathing (FB) and deep inspiration breath hold (DIBH) CT simulation scans were analyzed. The original PBA plans were re-calculated with MC. New proton plans that used MC for both optimization and dose calculation with equivalent CTV/ITV coverage were also created. A vRBE model, which uses a published model for DNA double strand break (DSB) induction, was applied on MC plans to study the potential impact of vRBE on cardiac doses. Comparative photon plans were generated on the DIBH scan. Results: Re-calculation of FB PBA plans with MC demonstrated significant under coverage of the ITV V99 and V95. Target coverage was recovered by re-optimizing the PT plan with MC with minimal change to OAR doses. Compared to photons with DIBH, MC-optimized FB and DIBH proton plans had significantly lower dose to the mean lung, lung V5, breast tissue, and spinal cord for similar target coverage. Even with application of vRBE in the proton plans, the putative increase in RBE at the end of range did not decrease the dosimetric advantages of proton therapy in cardiac substructures. Conclusions: MC should be used for PT treatment planning of mediastinal lymphoma to ensure adequate coverage of target volumes. Our preliminary data suggests that MC-optimized PT plans have better sparing of the lung and breast tissue compared to photons. Also, the potential for end of range RBE effects are unlikely to be large enough to offset the dosimetric advantages of proton therapy in cardiac substructures for mediastinal targets, although these dosimetric findings require validation with late toxicity data.

The American Society of Clinical Oncology has recommended tailoring palliative cancer care (PCC) to the distinct and complex needs of advanced cancer patients. The Supportive and Palliative Radiation Oncology (SPRO) service was initiated July 2011 to provide dedicated palliative radiation oncology (RO) care to cancer patients. We used care providers' ratings to assess SPRO's impact on the quality of PCC and compared perceptions of PCC delivery among physicians practicing with and without a dedicated palliative RO service. An online survey was sent to 117 RO care providers working at 4 Boston-area academic centers. Physicians and nurses at the SPRO-affiliated center rated the impact of the SPRO service on 8 PCC quality measures (7-point scale, "very unfavorably" to "very favorably"). Physicians at all sites rated their department's performance on 10 measures of PCC (7-point scale, "very poorly" to "very well"). Among 102 RO care providers who responded (response rate, 89% for physicians; 83% for nurses), large majorities believed that SPRO improved the following PCC quality measures: overall quality of care (physician/nurse, 98%/92%); communication with patients and families (95%/96%); staff experience (93%/84%); time spent on technical aspects of PCC (eg, reviewing imaging) (88%/56%); appropriateness of treatment recommendations (85%/84%); appropriateness of dose/fractionation (78%/60%); and patient follow-up (64%/68%). Compared with physicians practicing in departments without a dedicated palliative RO service, physicians at the SPRO-affiliated department rated the overall quality of their department's PCC more highly (P = .02). Clinicians indicated that SPRO improved the quality of PCC. Physicians practicing within this dedicated service rated their department's overall PCC quality higher than physicians practicing at academic centers without a dedicated service. These findings point to dedicated palliative RO services as a promising means of improving PCC quality.