Achievement of 10-year survival: A case of pubic bone recurrence as the primary failure site of chemo-refractory ovarian clear cell carcinoma

Skeletal system as a rare metastatic site in patients with ovarian carcinoma

OBJECTIVE

To evaluate the frequency and predictors of bone metastasis in patients with ovarian cancer and to determine prognostic factors associated with this finding.

METHODS

Patients diagnosed with ovarian cancer between January 2009 and December 2019 were evaluated. Patients with radiologically or pathologically confirmed bone metastasis were included in the study. Survival was analyzed using Kaplan-Meier curves and compared using the log-rank test. Multivariate analysis of prognostic factors related to survival was performed using the Cox proportional hazards model.

RESULTS

Nineteen (2.6%) of 736 patients had bone metastases. Patients with clear cell histology had a higher risk of bone metastases than patients with the other epithelial histology groups (12.3% vs 2.1%, p<0.001). Overall survival was significantly lower in patients diagnosed with bone metastasis at the time of cancer diagnosis than in those diagnosed with bone metastasis during the course of the disease (median 63 vs 6.1 months, p<0.001). However, when the survival time after the development of bone metastasis was examined, no difference was found between patients with metastasis at the time of diagnosis and at the time of first or later progression (median 13.6 vs 4 months, p=0.09). In addition, the median survival of patients with clear cell histology after bone metastasis did not differ statistically from that of patients with other epithelial histology (median 22 vs 7.5 months; p=0.13). In the clear cell subgroup, bone metastasis was an independent prognostic factor for survival after multivariate analysis. For all patients, the stage at diagnosis and serum CA125 and alkaline phosphatase levels at the time of bone metastasis were prognostic factors for survival.

DISCUSSION

Bone metastasis is rare in patients with ovarian cancer. However, the risk of bone metastasis is highest in patients with clear cell histology.

Updates of Pathogenesis, Diagnostic and Therapeutic Perspectives for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a special pathological type of epithelial ovarian carcinoma (EOC) and has a high prevalence in Asia without specific molecular subtype classification. Endometriosis is a recognized precancerous lesion that carries 3-fold increased risk of OCCC. Ovarian endometrioid carcinoma, which also originates from endometriosis, shares several features with OCCC, including platinum resistance and younger age at diagnosis. Patients with OCCC have about a 2.5 to 4 times greater risk of having a venous thromboembolism (VTE) compared with other EOC, and OCCC tends to metastasize through lymphatic vesicular and peritoneal spread as opposed to hematogenous metastasis. There is only mild elevation of the conventional biomarker CA125. Staging surgery or optimal cytoreduction combined with chemotherapy is a common therapeutic strategy for OCCC. However, platinum resistance commonly portends a poor prognosis, so novel treatments are urgently needed. Targeted therapy and immunotherapy are currently being studied, including PARP, EZH2, and ATR inhibitors combined with the synthetic lethality of ARID1A-dificiency, and MAPK/PI3K/HER2, VEGF/bFGF/PDGF, HNF1β, and PD-1/PD-L1 inhibitors. Advanced stage, suboptimal cytoreduction, platinum resistance, lymph node metastasis, and VTE are major prognostic predictors for OCCC. We focus on update pathogenesis, diagnostic methods and therapeutic approaches to provide future directions for clinical diagnosis and treatment of OCCC.