Current academic clinical trials in ovarian cancer: Gynecologic Cancer Intergroup and US National Cancer Institute Clinical Trials Planning Meeting, May 2009

Characteristics of Radiotherapy Trials Compared With Other Oncological Clinical Trials in the Past 10 Years

Importance

Modern precision radiotherapy is an innovative and effective treatment of cancer, yet it is unclear how radiotherapy trials are affected by expanding targeted and immune therapies and declining National Institutes of Health funding.

Objective

To analyze and compare the characteristics of radiotherapy trials with other oncological trials registered on ClinicalTrials.gov.

Design, Setting, and Participants

This is a cross-sectional analysis of trials registered on ClinicalTrials.gov between June 1, 2007, and May 8, 2017. Records of all 243 758 clinical studies registered by May 8, 2017, were downloaded, but only 25 907 interventional oncological trials registered between June 1, 2007, and May 8, 2017, and whose primary purpose was "treatment" were included in the final analysis. Trials were categorized according to cancer type and other registration information.

Main Outcomes and Measures

Characteristics of radiotherapy trials were compared with characteristics of other oncological trials. Chronological shifts in radiotherapy trials were also analyzed.

Results

Of the 25 907 trials selected, 1378 (5.3%) were radiotherapy trials and 24 529 (94.7%) were other oncological studies. The number of radiotherapy trials increased gradually from 94 (June 1, 2007, through May 31, 2008) to 192 (June 1, 2015, through May 31, 2016). Radiotherapy trials were less likely than other oncological studies to be registered before participant enrollment (763 of 1370 [55.7%] vs 16 105 of 24 434 [65.9%]; P < .001), to be blinded (45 of 1378 [3.3%] vs 2784 of 24 529 [11.3%]; P < .001), or to involve multiple geographic regions (2.4% vs 9.5%; P < .001), but they were more likely to be phase 2 to 3 (773 of 1124 [68.8%] vs 12 910 of 22 300 [57.9%]; P < .001) and to have a data-monitoring committee (839 of 1264 [66.4%] vs 11 728 of 21 060 [55.7%]; P < .001). Only a minority of radiotherapy trials were industry sponsored, which was significantly lower than for other oncological trials (80 of 1378 [5.8%] vs 10 651 of 24 529 [43.4%]; P < .001; adjusted odds ratio, 0.08; 95% CI, 0.06-0.10). The number of National Institutes of Health-sponsored radiotherapy trials decreased from 80 of 544 trials (14.7%) from 2007 to 2012 to 72 of 834 trials (8.6%) from 2012 to 2017 (P < .001). Radiotherapy trials with a sample size of more than 100 patients decreased from 155 of 543 trials (28.5%) from 2007 to 2012 to 157 of 833 trials (18.8%) from 2012 to 2017 (P < .001).

Conclusions and Relevance

The limited number of and the scarcity of funding for radiotherapy trials is concerning given the integral role of radiotherapy in the clinical management of patients with cancer worldwide. A multidisciplinary collaboration to promote and fund more radiotherapy research is warranted.

Rare ovarian tumours: Epidemiology, treatment challenges in and outside a network setting

PURPOSE OF THE REVIEW

More than 50% of all gynaecological cancers can be classified as rare tumours (defined as an annual incidence of <6 per 100,000) and such tumours represent an important challenge for clinicians.

RECENT FINDINGS

Rare cancers account for more than one fifth of all new cancer diagnoses, more than any of the single common cancers alone. Reviewing the RARECAREnet database, some of the tumours occur infrequently, whilst others because of their natural history have a high prevalence, and therefore appear to be more common, although their incidence is also rare. Harmonization of medical practice, guidelines and novel trials are needed to identify rare tumours and facilitate the development of new treatments. Ovarian tumours are the focus of this review, but we comment on other rare gynaecological tumours, as the diagnosis and treatment challenges faced are similar.

FUTURE

This requires European collaboration, international partnerships, harmonization of treatment and collaboration to overcome the regulatory barriers to conduct international trials. Whilst randomized trials can be done in many tumour types, there are some for which conducting even single arm studies may be challenging. For these tumours alternative study designs, robust collection of data through national registries and audits could lead to improvements in the treatment of rare tumours. In addition, concentring the care of patients with rare tumours into a limited number of centres will help to build expertise, facilitate trials and improve outcomes.

Regulatory T cells, inherited variation, and clinical outcome in epithelial ovarian cancer

The immune system constitutes one of the host factors modifying outcomes in ovarian cancer. Regulatory T cells (Tregs) are believed to be a major factor in preventing the immune response from destroying ovarian cancers. Understanding mechanisms that regulate Tregs in the tumor microenvironment could lead to the identification of novel targets aimed at reducing their influence. In this study, we used immunofluorescence-based microscopy to enumerate Tregs, total CD4 T cells, and CD8(+) cytotoxic T cells in fresh frozen tumors from over 400 patients with ovarian cancer (>80 % high-grade serous). We sought to determine whether Tregs were associated with survival and genetic variation in 79 genes known to influence Treg induction, trafficking, or function. We used Cox regression, accounting for known prognostic factors, to estimate hazard ratios (HRs) associated with T cell counts and ratios. We found that the ratios of CD8 T cells and total CD4 T cells to Tregs were associated with improved overall survival (CD8/Treg HR 0.84, p = 0.0089; CD4/Treg HR 0.88, p = 0.046) and with genetic variation in IL-10 (p = 0.0073 and 0.01, respectively). In multivariate analyses, the associations between the ratios and overall survival remained similar (IL-10 and clinical covariate-adjusted CD8/Treg HR 0.85, p = 0.031; CD4/Treg HR 0.87, p = 0.093), suggesting that this association was not driven by variation in IL-10. Thus, integration of novel tumor phenotyping measures with extensive clinical and genetic information suggests that the ratio of T cells to Tregs may be prognostic of outcome in ovarian cancer, regardless of inherited genotype in genes related to Tregs.

The ratios of CD8+ T cells to CD4+CD25+ FOXP3+ and FOXP3- T cells correlate with poor clinical outcome in human serous ovarian cancer

Ovarian cancer is an immune reactive malignancy with a complex immune suppressive network that blunts successful immune eradication. This suppressive microenvironment may be mediated by recruitment or induction of CD4⁺ regulatory T cells (Tregs). Our study sought to investigate the association of tumor-infiltrating CD4⁺CD25⁺FOXP3⁺ Tregs, and other immune factors, with clinical outcome in serous ovarian cancer patients. We performed immunofluorescence and quantification of intraepithelial tumor-infiltrating triple positive Tregs (CD4⁺CD25⁺FOXP3⁺), as well as CD4⁺CD25⁺FOXP3^-, CD3⁺ and CD8⁺ T cells in tumor specimens from 52 patients with high stage serous ovarian carcinoma. Thirty-one of the patients had good survival (i.e. > 60 months) and 21 had poor survival of < 18 months. Total cell counts as well as cell ratios were compared among these two outcome groups. The total numbers of CD4⁺CD25⁺FOXP3⁺ Tregs, CD4⁺CD25⁺FOXP3^-, CD3⁺ and CD8⁺ cells were not significantly different between the groups. However, higher ratios of CD8⁺/CD4⁺CD25⁺FOXP3⁺ Treg, CD8⁺/CD4⁺ and CD8/CD4⁺CD25⁺FOXP3^- cells were seen in the good outcome group when compared to the patients with poor outcome. These data show for the first time that the ratios of CD8⁺ to both CD4⁺CD25⁺FOXP3⁺ Tregs and CD4⁺CD25⁺FOXP3^- T cells are associated with disease outcome in ovarian cancer. The association being apparent in ratios rather than absolute count of T cells suggests that the effector/suppressor ratio may be a more important indicator of outcome than individual cell count. Thus, immunotherapy strategies that modify the ratio of CD4⁺CD25⁺FOXP3⁺ Tregs or CD4⁺CD25⁺FOXP3^- T cells to CD8⁺ effector cells may be useful in improving outcomes in ovarian cancer.

Comparison of advanced stage mucinous epithelial ovarian cancer and serous epithelial ovarian cancer with regard to chemosensitivity and survival outcome: a matched case-control study

Objective

The aim of this study was to compare clinicopathologic characteristics, surgery outcomes and survival outcomes of patients with stage III and IV mucinous epithelial ovarian cancer (mEOC) and serous epithelial ovarian carcinoma (sEOC).

Methods

Patients who had surgery for advanced stage (III or IV) mEOC were evaluated retrospectively and defined as the study group. Women with sEOC who were matched for age and stage of disease were randomly chosen from the database and defined as the control group. The baseline disease characteristics of patients and platinum-based chemotherapy efficacy (response rate, progression-free survival and overall survival [OS]) were compared.

Results

A total of 138 women were included in the study: 50 women in the mEOC group and 88 in the sEOC group. Patients in the mEOC group had significantly less grade 3 tumors and CA-125 levels and higher rate of para-aortic and pelvic lymph node metastasis. Patients in the mEOC group had significantly less platinum sensitive disease (57.9% vs. 70.8%; p=0.03) and had significantly poorer OS outcome when compared to the sEOC group (p=0.001). The risk of death for mEOC patients was significantly higher than for sEOC patients (hazard ratio, 2.14; 95% confidence interval, 1.34 to 3.42).

Conclusion

Advanced stage mEOC patients have more platinum resistance disease and poorer survival outcome when compared to advanced stage sEOC. Therefore, novel chemotherapy strategies are warranted to improve survival outcome in patients with mEOC.

Natural history and outcome of mucinous carcinoma of the ovary

OBJECTIVE

We performed a population-based analysis to compare the clinical characteristics of women with mucinous tumors with women with other epithelial tumors.

STUDY DESIGN

The Surveillance, Epidemiology, and End Results database was queried to identify all women with epithelial ovarian cancer diagnosed from 1988 to 2007. The natural history, clinical characteristics, and survival of women with serous tumors were compared with women with mucinous carcinomas.

RESULTS

A total of 40,571 women including 4811 with mucinous carcinomas (11.9%) were identified. Among women with stage I neoplasms, the presence of mucinous histology had no effect on either cancer-specific survival (hazard ratio, 0.87; 95% confidence interval, 0.74-1.04). Survival was inferior in patients with advanced-stage mucinous compared with serous tumors. The hazard ratio for cancer-specific survival for women with stage III mucinous tumors was 1.55 (95% confidence interval, 1.43-1.96).

CONCLUSION

Although survival for early-stage mucinous and serous tumors is similar, survival for advanced-stage mucinous neoplasms is inferior to that of serous carcinomas.