Background: Emerging mutations in the ESR1 gene that encodes for the estrogen receptor (ER) are associated with resistance to endocrine therapy. ESR1 mutations rarely exist in primary tumors (~ 1%) but are relatively common (10–50%) in metastatic, endocrine therapy-resistant cancers and are associated with a shorter progression-free survival. Little is known about the incidence and clinical implication of these mutations in early recurrence events, such as local recurrences or newly diagnosed metastatic disease. Methods: We collected 130 archival tumor samples from 103 breast cancer patients treated with endocrine therapy prior to their local/metastatic recurrence. The cohort consisted of 41 patients having at least 1 sample from local/loco-regional recurrence and 62 patients with metastatic disease (of whom 41 newly diagnosed and 28 with advanced disease). The 5 most common ESR1 hotspot mutations (D538G, L536R, Y537S/N/C) were analyzed either by targeted sequencing or by droplet digital PCR. Progression-free survival (PFS), disease-free survival (DFS), and distant recurrence-free survival (DRFS) were statistically tested by Kaplan-Meier analysis. Results: The prevalence of ESR1 mutations was 5/41 (12%) in newly diagnosed metastatic patients and 5/28 (18%) for advanced metastases, detected at allele frequency > 1%. All mutations in advanced metastases were detected in patients previously treated with both tamoxifen (TAM) and aromatase inhibitors (AI). However, in newly diagnosed metastatic patients, 4/5 mutations occurred in patients treated with TAM alone. PFS on AI treatment in metastatic patients was significantly shorter for ESR1 mutation carriers (p = 0.017). In the local recurrence cohort, ESR1 mutations were identified in 15/41 (36%) patients but only 4/41 (10%) were detected at allele frequency > 1%. Again, most mutations (3/4) were detected under TAM monotherapy. Notably, 1 patient developed ESR1 mutation while on neoadjuvant endocrine therapy. DFS and DRFS were significantly shorter (p = 0.04 and p = 0.017, respectively) in patients that had ESR1 mutations (> 1%) in their loco-regional recurrence tumor. Conclusions: Clinically relevant ESR1 mutations are prevalent in newly diagnosed metastatic and local recurrence of endocrine-treated breast cancer. Since local recurrences are amenable to curative therapy, these mutations may inform the selection of subsequent endocrine therapies.

Lutetium-177-PSMA ([177Lu]-PSMA-617), a radiolabeled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA), enabling targeted radiation therapy to metastatic prostate lesions. Our objective was to retrospectively analyze the activity of [177Lu]-PSMA-617 given off-trial to men with metastatic castration resistant prostate cancer (mCRPC) and identify clinical factors associated with PSA response. Electronic medical records of all men treated with [177Lu]-PSMA-617 were reviewed and analyzed. Overall survival was calculated using the Kaplan–Meier method. The association between potential variables and PSA response was analyzed by univariate analysis, using either logistic regression or χ²/Fisher’s exact test. Multivariable analysis was carried out using logistic regression on all categorical variables with a P-value of 20%. A score combining these two parameters was significantly associated with PSA response. In summary, [177Lu]-PSMA-617 is active in the ‘real-life’ setting of heavily pretreated men with mCRPC.

Background: Prostate cancer is a common malignancy of the elderly, and with the aging of the population, the need is growing for therapies suitable for this age group. Lutetium-177–prostate-specific membrane antigen (Lu-PSMA), a radiolabeled small molecule, binds with high affinity to prostate-specific membrane antigen, enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). In a recent single-arm phase II trial and a subsequent expansion cohort, a prostate-specific antigen (PSA) decline of ≥50% was observed in approximately 60% of patients receiving Lu-PSMA. Taking into account the specific challenges and potential toxicities of Lu-PSMA administration in elderly men, we sought to retrospectively analyze the safety and activity of Lu-PSMA in men aged older than 75 years with mCRPC. Patients and Methods: The electronic medical records of 24 patients aged older than 75 years treated with Lu-PSMA “off-trial” were reviewed, and clinical data were extracted. Clinical endpoints were toxicity and activity, defined as a PSA decline ≥50%. Descriptive statistics were performed using Excel. Results: The median age at treatment start was 81.7 years (range 75.1–91.9). The median number of previous treatment lines was four. The number of treatment cycles ranged from one to four; the mean administered radioactivity was 6 GBq per cycle. Treatment was generally tolerable; side effects included fatigue (n = 8, 33%), anemia (n = 7, 29%), thrombocytopenia (n = 5, 21%), and anorexia/nausea (n = 3, 13%). Clinical benefit was observed in 12 of 22 patients (54%); PSA decline above 50% was observed in 11 patients (48%) and was associated with significantly longer overall survival. Conclusion: Our results indicate that Lu-PSMA is safe and active in elderly patients with mCRPC. Implications for Practice: Lutetium-177–prostate-specific membrane antigen (Lu-PSMA), a radiolabeled small molecule, binds with high affinity to prostate-specific membrane antigen, enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). The recently published single-arm phase II trial with Lu-PSMA, describing its safety and activity, did not include patients aged older than 75 years. In this study, Lu-PSMA activity was retrospectively analyzed in patients aged older than 75 years and results indicate that treatment was tolerable and similarly active in this age group, with no new emerging safety signals. Despite the small cohort size, this analysis suggests that Lu-PSMA can serve as an advanced palliative treatment line in mCRPC in elderly patients.

Immunotherapy has transformed the landscape of treatment in metastatic renal cell carcinoma (mRCC) in the last decade. Currently, prognostic risk stratification is based on the model developed in the era of vascular endothelial growth factor receptor inhibitors (VEGFRi) by Heng in 2009. Our study aims to find the most relevant risk criteria for mRCC patients treated with checkpoint inhibitors (CPI). In a retrospective cohort study, laboratory, pathology, demographic, and clinical data were retrieved from electronic medical records of consecutive mRCC patients treated with CPI in a tertiary center between 2015 and 2020. An unbiased multivariate analysis was performed to define predictive variables with a bootstrap validation step. We analyzed data on 127 patients with a median follow-up of 60 months. The median overall survival (OS) since the diagnosis of metastatic disease was 57 months. The response rate for CPI was 39%. Five risk factors were correlated with worse OS: intact primary kidney tumor (HR 2.33, p = 0.012), liver metastasis (HR 3.33, p = 0.001), <one year to treatment start (HR 1.98, p = 0.029), elevated platelets (HR 3.06, p = 0.015), and Karnofsky performance status <80% (HR = 3.42, p = 0.001). The model received a C-index of 70.7 compared with a score of 62.0 for the Heng’s model. When dividing patients into “low-risk” (0–1 risk factors) and “high-risk” (2–5 risk factors), there was good separation between the groups, with an HR of 5.9 (p < 0.0001). This study presents a new prognostic model for mRCC in the immunotherapy era with improved accuracy. Further research is needed to validate this model in larger cohorts.

Immune checkpoint inhibitors (CPI) are indicated for metastatic renal cell carcinoma (mRCC). Immune-related thyroiditis (irT), an immune-related adverse event (irAE), affects up to 30% of patients. We aimed to determine whether irT is associated with overall survival in mRCC. A retrospective cohort study of 123 consecutive patients treated with CPI for mRCC in a single center between 2015 and 2020 was conducted. Disease risk stratification was assessed by two methods: Heng criteria and a novel dichotomic stratification system to “Low risk” versus “High risk” adding number of metastatic sites. Thirty-eight percent of patients developed irT. In the general cohort, irT was not associated with a survival benefit. However, irT was associated with better survival in the poor risk group per Heng criteria (n = 17, HR = 0.25, p = 0.04) and in the novel “High risk” group (HR = 0.28, n = 42, p = 0.01), including after accounting for covariates in multivariate analysis (HR = 0.27, p = 0.003). Having any irAE was associated with improved survival in the whole cohort, with no significant correlation of any specific irAE, in either the whole cohort or the “High risk” group. We conclude that irT is an early and prevalent irAE, associated with prolonged survival in patients with poor/“High” risk mRCC.

Immune checkpoint inhibitors (ICIs) are now the standard of care for metastatic urothelial carcinoma (mUC) patients. Our aim was to describe the activity of ICIs in mUC and find the clinical parameters associated with response. This is a retrospective, single-center chart review of mUC patients receiving ICIs. The overall survival (OS) was plotted using the Kaplan–Meier method and was compared using a log-rank test. Associations between the variables and responses were analyzed by univariate and multivariable analyses, using either logistic regression or a Chi-square/Fisher’s exact test. Ninety-four patients received ICIs, 85% of which were in the second line or beyond; the median age was 71.8 years, and 82% were men. Six (6.4%), 11 (11.7%), 7 (7.4%) and 70 (74.5%) patients achieved a complete response (CR), partial response (PR), mixed response/stable disease (M/SD) or progressive disease (PD), respectively. The median overall survival was 3.2 months for the entire cohort and was significantly different according to the response pattern—not reached, 32.3, 6.4 and 2.0 months for CR, PR, M/SD and PD, respectively. The response was not significantly associated with the line of treatment. ‘Site of metastasis’ was associated with the response, and the absolute neutrophil count was borderline associated with the response. In summary, we found a substantial variance in the potential benefit from ICIs in mUC, emphasizing the need for predictive biomarkers and frequent monitoring of mUC patients receiving ICIs.