Prognostic value of cystocopically pseudotumoral lesions (inflammation/granuloma) in primary stage T1 grade 3 bladder tumors treated with BCG

Adaptive Immunity in Genitourinary Cancers

CONTEXT

While urothelial and renal cell cancers have exhibited modest responses to novel immune checkpoint inhibitors targeting the programmed death ligand 1 and its receptor, response rates in patients with prostate cancer have remained poor. The factors underlying suboptimal outcomes observed in patients treated with novel immunotherapies are still to be resolved.

OBJECTIVE

To review the literature and describe the key adaptive immune physiological events associated with cancer progression and therapeutic response in genitourinary (GU) cancers.

EVIDENCE ACQUISITION

We performed a nonsystematic, collaborative narrative review to highlight recent advancements leading to the current state of knowledge on the critical mediators of antitumor adaptive immunity to GU cancers. Further, we discuss the findings on the pre- and post-treatment immunological events that either are unique to each of the three cancer types or exhibit overlapping clinical associations.

EVIDENCE SYNTHESIS

Aging-associated immune function decline is a major factor underlying poor outcomes observed in patients treated with both conventional and novel immunotherapies. Other cancer immunobiological aspects associated with suboptimal responses in GU cancers include the overall tumor mutational burden, mutations in specific tumor suppressor/DNA damage repair genes (KDM6A, PTEN, STAG2, TP53, ATM, and BRCA2), and abundance of multiple functional states of adaptive immune cells and their spatiotemporal localization within the tumor immune microenvironment. Understanding these mechanisms may potentially lead to the development of prognostic and predictive biomarkers such as immune cell infiltration profiles and tertiary lymphoid structures (TLSs) that associate with variable clinical outcomes depending on the nature of the novel immunotherapeutic approach. Implementation of newer immune-monitoring technologies and improved preclinical modeling systems will augment our understanding of the host and tumor intrinsic factors contributing to the variability of responses to immunotherapies.

CONCLUSIONS

Despite the tremendous progress made in the understanding of dynamic and static adaptive immune elements within the tumor immune landscape, several knowledge gaps remain. A comprehensive knowledge thus gained will lead to precision immunotherapy, improved drug sequencing, and a therapeutic response.

PATIENT SUMMARY

We performed a collaborative review by a diverse group of experts in the field to examine our understanding of the events and crosstalk between cancer cells and the patient's immune system that are associated with responses to novel immunotherapies. An evolving understanding of tumor-intrinsic and host-related immune alterations, both before and after therapy, will aid in the discovery of promising markers of responses to immunotherapy as well as the development of unique therapeutic approaches for the management of genitourinary cancers.

Trained immunity as a molecular mechanism for BCG immunotherapy in bladder cancer

Intravesical BCG instillation is the gold-standard adjuvant immunotherapy for patients with high-risk non-muscle-invasive bladder cancer. However, the precise mechanism of action by which BCG asserts its beneficial effects is still unclear. BCG has been shown to induce a non-specific enhancement of the biological function in cells of the innate immune system, creating a de facto heterologous immunological memory that has been termed trained immunity. Trained immunity or innate immune memory enables innate immune cells to mount a more robust response to secondary non-related stimuli after being initially primed (or trained) by a challenge such as BCG. BCG-induced trained immunity is characterized by the metabolic rewiring of monocyte intracellular metabolism and epigenetic modifications, which subsequently lead to functional reprogramming effects, such as an increased production of cytokines, on restimulation. Results from BCG vaccination studies in humans show that trained immunity might at least partly account for the heterologous beneficial effects of BCG vaccination. Additionally, immunity might have a role in the effect of BCG immunotherapy for bladder cancer. Based on these indications, we propose that trained immunity could be one of the important mechanisms mediating BCG immunotherapy and could provide a basis for further improvements towards a personalized approach to BCG therapy in non-muscle-invasive bladder cancer.

Natural course of asymptomatic abnormal prostate findings incidentally detected by CT after intravesical BCG therapy

BACKGROUND

Detailed information is not currently available on the incidence, natural course, and management of asymptomatic abnormal prostate findings incidentally detected by radiologic evaluations after BCG therapy for non-muscle-invasive bladder cancer patients.

METHODS

We identified 38 patients who were evaluated by contrast-enhanced CT scans before TUR-BT and after BCG therapy between 2006 and 2012. We evaluated the clinical courses of patients with abnormal radiologic findings of the prostate gland after BCG therapy.

RESULTS

Abnormal findings on CT scans were found in the prostate glands of 11 of the 38 patients examined (28.9%), none of whom exhibited any sign or symptom associated with prostatitis. Abnormal findings included a low attenuation area (n = 6, 15.8%), contrast enhancement (n = 3, 7.9%), and a low attenuation area and contrast enhancement in the prostate gland (n = 2, 5.3%). During the follow-up, abnormal prostate findings disappeared spontaneously in most cases without any anti-bacterial or anti-tuberculous drug treatments. No significant differences were observed in patient clinical backgrounds, with the exception of post-BCG prostate volumes, between patients with and without abnormal CT findings. Furthermore, no significant differences were noted in the incidence of the adverse effects of BCG therapy, tumor recurrence rates, or progression rates between patients with and without abnormal CT findings of the prostate gland after BCG therapy.

CONCLUSIONS

Asymptomatic abnormal prostate findings incidentally detected by CT after BCG therapy are not rare, and these disappear over time during the follow-up period without any treatment.