Tumor heterogeneity of fibroblast growth factor receptor 3 (FGFR3) mutations in invasive bladder cancer: implications for perioperative anti-FGFR3 treatment

BACKGROUND

Fibroblast growth factor receptor 3 (FGFR3) is an actionable target in bladder cancer. Preclinical studies show that anti-FGFR3 treatment slows down tumor growth, suggesting that this tyrosine kinase receptor is a candidate for personalized bladder cancer treatment, particularly in patients with mutated FGFR3. We addressed tumor heterogeneity in a large multicenter, multi-laboratory study, as this may have significant impact on therapeutic response.

PATIENTS AND METHODS

We evaluated possible FGFR3 heterogeneity by the PCR-SNaPshot method in the superficial and deep compartments of tumors obtained by transurethral resection (TUR, n = 61) and in radical cystectomy (RC, n = 614) specimens and corresponding cancer-positive lymph nodes (LN+, n = 201).

RESULTS

We found FGFR3 mutations in 13/34 (38%) T1 and 8/27 (30%) ≥T2-TUR samples, with 100% concordance between superficial and deeper parts in T1-TUR samples. Of eight FGFR3 mutant ≥T2-TUR samples, only 4 (50%) displayed the mutation in the deeper part. We found 67/614 (11%) FGFR3 mutations in RC specimens. FGFR3 mutation was associated with pN0 (P < 0.001) at RC. In 10/201 (5%) LN+, an FGFR3 mutation was found, all concordant with the corresponding RC specimen. In the remaining 191 cases, RC and LN+ were both wild type.

CONCLUSIONS

FGFR3 mutation status seems promising to guide decision-making on adjuvant anti-FGFR3 therapy as it appeared homogeneous in RC and LN+. Based on the results of TUR, the deep part of the tumor needs to be assessed if neoadjuvant anti-FGFR3 treatment is considered. We conclude that studies on the heterogeneity of actionable molecular targets should precede clinical trials with these drugs in the perioperative setting.

Locomotor performance in highly-trained young soccer players: does body size always matter?

To examine the effects of body size on locomotor performance, 807 15-year-old French and 64 Qatari soccer players participated in the present study. They performed a 40-m sprint and an incremental running test to assess maximal sprinting (MSS) and aerobic speeds, respectively. French players were advanced in maturity, taller, heavier, faster and fitter than their Qatari counterparts (e.g., Cohen's d=+1.3 and + 0.5 for body mass and MSS). However, when adjusted for body mass (BM), Qatari players had possibly greater MSS than French players (d=+0.2). A relative age effect was observed within both countries, with the players born in the first quarter of the year being taller, heavier and faster that those born during the fourth quarter (e.g., d=+0.2 for MSS in French players). When directly adjusted for BM, these MSS differences remained (d=+0.2). Finally, in both countries, players selected in National teams were taller, heavier, faster and fitter than their non-selected counterparts (e.g., d=+0.6 for MSS in French players), even after adjustments for body size (d=+0.5). Differences in locomotor performances between players with different phenotypes are likely mediated by differences in body size. However, when considering more homogeneous player groups, body dimensions are unlikely to substantially explain the superior locomotor performances of older and/or international players.

Milk fat globule--epidermal growth factor--factor VIII (MFGE8)/lactadherin promotes bladder tumor development

Milk fat globule-epidermal growth factor-factor VIII (MFGE8), also called lactadherin or SED1, is a secreted integrin-binding protein that promotes elimination of apoptotic cells by phagocytes leading to tolerogenic immune responses, and vascular endothelial growth factor (VEGF)-induced angiogenesis: two important processes for cancer development. Here, by transcriptomic analysis of 228 biopsies of bladder carcinomas, we observed overexpression of MFGE8 during tumor development, correlated with expression of genes involved in cell adhesion or migration and in immune responses, but not in VEGF-mediated angiogenesis. To test whether MFGE8 expression was instrumental in bladder tumor development, or a simple consequence of this development, we used genetic ablation in a mouse model of carcinogen-induced bladder carcinoma. We showed that Mfge8 was also upregulated in mouse carcinoma, and that in its absence, Mfge8-deficient animals developed less advanced tumors. Angiogenesis was similar in carcinogen-treated Mfge8-expressing or -deficient bladders, thus ruling out a major role of the proangiogenic function of Mfge8 for its protumoral role. By contrast, the tumor-promoting role of Mfge8 was not observed anymore in mice devoid of adaptive immune system, and human tumors overexpressing MFGE8 where invaded with macrophages and regulatory T cells, thus suggesting that MFGE8/lactadherin favors development of bladder tumors at least partly by an immune system-dependent mechanism. Our observations suggest future use of MFGE8-inhibiting molecules as therapies of bladder carcinomas, and of a limited number of other human cancers, in which our analysis of public databases also revealed overexpression of MFGE8.

T helper 1/2 lymphocyte urinary cytokine profiles in responding and nonresponding patients after 1 and 2 courses of bacillus Calmette-Guerin for superficial bladder cancer

PURPOSE

Interleukin (IL)-2 and interferon-gamma are released during T helper 1 lymphocyte responses and IL-10 is released during T helper 2 lymphocyte responses. We have previously reported that a T helper 1 lymphocyte urinary cytokine profile is associated with a favorable prognosis after bacillus Calmette-Guerin (BCG) treatment. We evaluated the T helper 1/2 lymphocyte cytokine profiles during courses 1 and 2 of 6 weekly BCG instillations.

MATERIALS AND METHODS

Urinary interferon-gamma, IL-2 and IL-10 were measured by enzyme-linked immunosorbent assay after each of 6 weekly instillations of 150 mg. BCG, Pasteur strain, in 19 patients with superficial stages Ta and T1 bladder cancer, and carcinoma in situ. The 11 patients who did not respond to course 1 were re-treated according to the same schedule and reevaluated.

RESULTS

During course 1 interferon-gamma was higher than during course 2 (p <0.001), which was associated with nonrecurrence (p <0.001). In contrast, IL-2 cytokine was higher after course 2 (p <0.01), which was associated with a BCG response (p = 0.01). Interferon-gamma and IL-10 correlated during courses 1 and 2 (p = 0.04 and 0.0004, respectively). We distinguished groups 1-immediate T helper 1 lymphocyte profile consisting of responders to course 1 with high interferon-gamma, IL-2 and IL-10, 2-delayed T helper 1 lymphocyte profile consisting of responders to course 2 with early high IL-2 and 3-consisting of nonresponders to the 2 courses with low interferon-gamma, IL-2 and IL-10.

CONCLUSIONS

A T helper 1 lymphocyte urinary cytokine profile was associated with a clinical response to BCG. A repeat BCG course induces a favorable immune response in a subset of patients, suggesting that maintenance therapy may be beneficial.

Clonality of tumor-infiltrating lymphocytes in human urinary bladder carcinoma

The immune system has been implicated in the control of bladder tumor growth. To evaluate the clonality of bladder tumor-infiltrating T lymphocytes (TILs) in vivo, we studied the T-cell antigen receptor (TCR) repertoire in tumor biopsy specimens from 10 patients with transitional-cell carcinoma (TCC) of the bladder. Nine patients had a primary tumor, and one had a multifocal disease, consisting of two bladder tumors and three bilateral upper urinary tract sites of involvement. The following specimens from the nine patients with a primary tumor also were analyzed: a recurrent tumor from four patients, a metastatic lymph node from one patient, and peripheral blood from five patients. We used a high-resolution polymerase chain reaction (PCR) method to determine CDR3 (complementarity-determining region 3) size lengths of TCR beta-chain transcripts. Oligoclonal T-cell expansion was identified in all specimens, with a larger number of expanded clones in the tumors than in peripheral blood. Expanded clones were identified in several beta-chain variable region (BV) subfamilies and varied from one patient to the next and also in different specimens from the same patient. However, a number of clones with the same VJ combination and the same CDR3 size were identified in a given patient (in specimens collected either simultaneously or at different times), suggesting homogeneity in the immunogenic environment. Clonal T-cell expansion in patients with bladder cancer may reflect prolonged exposure of T lymphocytes to tumor antigens. Our findings provide a basis for functional studies to elucidate T lymphocyte-bladder tumor cell interactions.

Evaluation of local immune response after intravesical bacille Calmette-Guérin treatment for superficial bladder cancer

OBJECTIVE

To help define the optimal protocol of Bacille Calmette-Guérin (BCG) treatment for transitional cell carcinoma (TCC) of the bladder by examining cytokine production and antigen presentation to effector cells after instillations of BCG in patients with bladder TCC.

PATIENTS AND METHODS

Sixty-four urine samples from 11 patients were tested for the production of interferon gamma (IFN-gamma) using a modified commercial enzyme-linked immunosorbent assay (ELISA) kit. Urine was collected before and at intervals up to 24 h after the intravesical instillation of BCG. Immunohistological studies were also carried out using a two-step alkaline phosphatase technique to explore the expression of tumour-associated antigens (TAAs) (E7, 19A211, T138), major histocompatibility complex (MHC) molecules and lymphocyte subset infiltrates (CD3, CD4, CD8) in bladder biopsies before and 3 weeks after the completion of treatment in seven patients.

RESULTS

IFN-gamma was only detected 4, 6 and 8 h after instillation, with a maximum concentration at 6 h (2.9-34.7 IU/mL in 10 patients). During a 6-week course of BCG, IFN-gamma was barely detectable after the first two instillations, but gradually increased from the third instillation onwards. TAA and MHC II antigens, which were absent or faintly expressed on normal urothelial cells before treatment, were expressed strongly in five patients after treatment. The local recruitment of immunocompetent cells was detected in all patients.

CONCLUSION

These results suggest that the local immune response after the intravesical instillation of BCG can be quantified using simple ELISA tests and could be useful in defining objective criteria for rationalizing treatment (dose and duration), and in determining the relation between the immune response and anti-tumour activity. There is evidence that antigen presentation is enhanced after BCG instillations, suggesting that a T cell-MHC restricted pathway might be involved in the anti-tumour response. This study supports the search for tumour-rejection antigens in bladder cancer.