Immunotherapy in the Elderly

CONTEXT

Immunotherapy has historic and contemporary presence in prostate, urothelial (UC), and renal cell (RCC) carcinomas. However, robust data on utility and generalizability of these treatments in older patients are lacking.

OBJECTIVE

To systematically evaluate evidence regarding the efficacy and safety of immunotherapy in elderly patients with prostate cancer, UC, or RCC.

EVIDENCE ACQUISITION

PubMed/Medline, Embase, Web of Knowledge, and Cochrane Library databases were searched up to October 2017 and according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. A narrative review of studies was performed.

EVIDENCE SYNTHESIS

Twenty-one reports were included regarding prostate cancer (four studies), UC (eight), and RCC (nine). In prostate cancer, sipuleucel-T improves survival (median age >70 yr) and similar results were seen in the PROSTVAC phase 2 trial. Ipilimumab has not improved survival independent of age; data for programmed cell death 1 inhibition is evolving. In metastatic UC, ≥50% of patients enrolled in pivotal checkpoint inhibitor studies were aged ≥65 yr. Three studies reported similar objective response rates (ORRs) in patients aged <65 versus ≥65 yr, whereas one study reported comparable ORRs in patients <80 versus ≥80 yr. In metastatic RCC, cytokine studies showed no efficacy difference by age; one study reported more ≥grade 3 toxicity in patients aged ≥65 yr. One vaccine-based study suggests that older age was associated with shorter survival. The benefit of nivolumab in second-line therapy was more apparent for patients aged 65-<75 yr than for those aged ≥75 yr. Across tumor subtypes, immunotherapy was well tolerated with minimal data stratifying toxicity by age.

CONCLUSIONS

Contemporary immunotherapy has informed practice in genitourinary malignancies independent of patient age. Trial reporting of outcomes by age will be important to understand the generalizability of ongoing investigations for elderly patients.

PATIENT SUMMARY

With the growing use of immunotherapy in genitourinary malignancies, benefits appear to apply independent of age. As the field advances, detailed reporting on outcomes and toxicities by age will be informative for both patients and physicians when discussing treatment options.

TNFR2: A Novel Target for Cancer Immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but exhibit variable efficacy and relapse and can induce autoimmunity. Tumor necrosis factor (TNF) receptor 2 (TNFR2) is a signaling molecule found on the surface of a subset of potent regulatory T cells (T_regs) that can activate the proliferation of these cells through nuclear factor kappa B (NF-κB). TNFR2 is also abundantly expressed on the surface of many human tumors. We propose that blocking TNFR2 might target abundant TNFR2⁺ tumor-infiltrating T_regs and directly kill TNFR2-expressing tumors. We also posit that TNFR2 inhibitors might potentially constitute safer and more targeted alternatives to ICI cancer treatment because the expression of TNFR2 on immune cells, concentrated in the tumor microenvironment of various cancers, appears to be more selective than that of checkpoint molecules.

Expression and Functional Characterization of the BNIP3 Protein in Renal Cell Carcinomas

BNIP3 (Bcl-2/adenovirus E1B 19-kDa interacting protein 3) is a BH3-only protein that regulates apoptosis and autophagy. BNIP3 plays also an important role in hypoxia-induced cell response and is regulated by HIF1. Here, we studied a possible association of BNIP3 expression and the prognosis of patients with renal cell carcinomas (RCCs) and examined the functional relevance of BNIP3 in the regulation of cell survival and apoptosis of renal carcinoma cells. BNIP3 expression was determined by immunohistochemistry in RCC tumor tissue samples of 569 patients using a tissue microarray. Functional characterization of BNIP3 in renal carcinoma cells indicates prosurvival effects. In human RCC tumor samples, high cytoplasmic BNIP3 expression was associated with high-grade RCCs and regional lymph node metastasis. BNIP3 expression correlated negatively with disease-specific survival. Multivariate Cox regression analysis retained BNIP3 expression as an independent prognostic factor in patients without distant metastasis. Together, our studies imply that BNIP3 regulates cell survival in RCCs and its expression is an independent prognostic marker in patients with localized RCCs.