Stereotactic radiosurgery for melanoma brain metastases: dose-size response relationship in the era of immunotherapy.

PURPOSE/OBJECTIVE(S): To determine, for intact melanoma brain metastases (MBM) treated with single-fraction stereotactic radiosurgery (SRS), whether planning parameter peripheral dose per lesion diameter (PDLDm, Gy/mm) and lesion control (LC) differs with versus without immunotherapy (IO). MATERIALS/METHODS: We performed a retrospective analysis of patients with intact MBM treated with SRS from 2008 to 2019. Cox-frailty models were constructed to include confounders selected by penalized Cox regression models with a LASSO selector. Interaction effect testing was used to determine whether a significant effect between IO and PDLDm could be demonstrated with respect to LC. RESULTS: The study cohort comprised 67 patients with 244 MBMs treated with SRS (30 patients with 122 lesions treated with both SRS and IO) were included. The logarithm of PDLDm was selected as a predictor of LC (HR 0.307, 95% CI 0.098-0.441), adjusting for IO receipt (HR 0.363, 95% CI 0.108-1.224). Interaction effect testing demonstrated a differential effect of PDLDm by IO receipt, with respect to LC (p = 0.048). Twelve-month LC rates for a 7.5 mm lesion receiving SRS (18 Gy) with IO versus without IO were 87.8% (95% CI 69.0-98.3%) versus 79.8% (95% CI 55.1-93.8%) respectively. CONCLUSION: PDLDm predicted LC in patients with small MBMs treated with single-fraction SRS. We found a differential effect of dose per lesion size and LC by immunotherapy receipt. Future studies are needed to determine whether lower doses of single-fraction SRS afford similarly effective LC for patients with small MBMs receiving immunotherapy.

The effect of omission of adjuvant radiotherapy after neoadjuvant chemotherapy and breast conserving surgery with a pathologic complete response.

OBJECTIVE(S): Neoadjuvant chemotherapy (NAC) is a standard of care for locally advanced breast cancers. Adjuvant radiotherapy (RT) after NAC is an area of active research. We hypothesize overall survival (OS) is not altered by omitting RT in women with a pathologic complete response (pCR) to NAC after breast conserving survery (BCS). METHODS: Patients from the National Cancer Database who underwent NAC, BCS, and had a pCR were included. Inflammatory disease, <6 months follow up, and unknown variables were excluded. Descriptive statistics characterized the retained cohort. Logistic regression analyzed the influence of variables on the rate of RT omission. Cox proportional hazard modeling analyzed the influence of prognostic variables on OS. RESULTS: Of 5383 women included, 364 (7%) omitted RT. 5-year OS was 94.1% with RT, 93% without. RT omission was most likely in women >70yo (adjusted OR2.4, 95%CI 1.58-3.65, p < .0001;reference 40-49 yo), Hispanic (AOR 1.73, 95%CI 1.19-2.52, p = .0044; reference non-Hispanic), ≥20 miles from treatment facility (20-49 miles; AOR 1.45, 95%CI 1.09-1.93, p = .0109: >50 miles; AOR 2.02, 95%CI 1.42-2.87, p < .0001;reference 0-19 miles), grade 1 (AOR 4.29, 95%CI 2.16-8.51, p < .0001; reference grade 3), and clinical T4 disease (AOR 3.17, 95%CI 1.74-5.79, p = .0002; reference T0/1). Women ≥60yo (60-69: AHR 2.33, 95%CI 1.41-3.83, p = .0009:70+:AHR 2.4, 95%CI 1.24-4.62, p = .0092; reference 40-49) and with N1 and N3 disease (N1: AHR 1.67, 95% CI 2.28-3.24, p = .0034; N3: AHR3.37,95%CI2.01-5.65,p < .0001) showed increased death. Triple-positive (AHR 0.18, 95%CI 0.07-0.43, p = .0002) and HER2+ patients (AHR 0.44, 95%CI 0.30-0.64, p < .0001) had improved OS compared to triple-negative disease. No survival difference was seen with omission of RT (log-rank test: p = .1783; Cox model AHR 1.33, 95%CI 0.76-2.31, p = .3181). CONCLUSION: Women ≥70, of Hispanic origin, living ≥20 miles from treatment facility, and grade 1 disease were more likely to omit RT. HER2+ patients had favorable OS, while older age and N3 disease were negative prognostic factors. Omitting RT after a pCR to NAC and BCS was not found to affect OS.

Extrapulmonary small cell carcinoma: Prognostic factors, patterns of care, and overall survival.

BACKGROUND: Extrapulmonary small cell carcinoma is a rare malignancy with scarce data. Treatment paradigms extrapolate from pulmonary small cell carcinoma and single institution studies. We analyzed the epidemiology, patterns of care, prognostic factors, and overall survival (OS) of EPSCC patients. METHODS: The cohort included EPSCC. Patients with <2 months follow-up, unknown demographic/treatment variables were excluded. Descriptive statistics were performed to characterize the cohort. Kaplan-Meier methods were used to estimate OS. Cox proportional hazard modeling was done to analyze the influence of prognostic variables on OS. RESULTS: 5747 patients were included. Median OS was 1.2 years. Head and neck (HR: 0.60, 95% CI 0.53-0.67, p < 0.0001) and breast (HR: 0.69, 95% CI 0.53-0.89, p = .0046) were associated with improved OS; gastrointestinal (HR: 1.19, 95% CI 1.09-1.29, p < .0001) worse OS; and gynecologic (HR: 1.04, 95% CI 0.92-1.17, p = .5660) showing no difference, all compared to genitourinary (reference). Surgery was associated with improved overall survival (HR: 0.84, 95% CI 0.79-0.91, p=<.0001). Chemoradiation showed a decreased HR (HR: 0.91, 95% CI 0.83-0.99, p = .0363) when compared to chemotherapy alone (reference). CONCLUSION: EPSCC occurs throughout the body with poor survival. Anatomic subsite was predictive for survival. Surgical resection may improve survival. Concurrent chemoradiation appears to improve survival over chemotherapy alone.

Anaplastic thyroid cancer: Prognostic factors, patterns of care, and overall survival.

BACKGROUND: Anaplastic thyroid cancer (ATC) represents a rare, aggressive malignancy. We analyzed factors predictive for overall survival (OS) and treatment modality utilization. METHODS: Using the National Cancer Data Base, we identified 3552 patients with ATC. Factors associated with surgery, high-dose radiotherapy (RT; ≥59.4 Gy), and chemotherapy utilization were evaluated using multivariable logistic regression. From this, an inverse probability-weighted propensity score was incorporated into multivariable Cox regression analyses for OS. RESULTS: Numerous factors predictive for high-dose RT, total thyroidectomy, and chemotherapy utilization are described. Factors associated with improved survival were absence of clinical or pathologic lymph node involvement, absence of metastasis, tumor size ≤6 cm, negative surgical margins, surgery, RT, and chemotherapy. On conditional landmark analysis, improved survival seen with chemotherapy and surgery other than total thyroidectomy was lost, but persisted for total thyroidectomy and high-dose RT. CONCLUSION: Even after correction for selection and immortal time bias, high-dose RT resulted in improved survival. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2083-E2090, 2016.