Ovarian and peritoneal psammocarcinoma: Results of a multicenter study on 25 patients

Unfavorable carcinoma of unknown primary with a gastrointestinal profile: a retrospective study

BACKGROUND

Carcinoma of unknown primary (CUP) with a gastrointestinal profile is categorized by the European Society of Medical Oncology (ESMO) guidelines into favorable and unfavorable subsets. Favorable CUPs benefit from site-specific chemotherapy (CT), while the optimal treatment for unfavorable CUPs is still undefined.

MATERIALS AND METHODS

We conducted a single-center retrospective study to describe outcomes of patients with CUP with a gastrointestinal profile referred to our center from January 2000 to August 2023. Favorable CUPs were defined as CK7-/CK20+/CDX2+ by immunohistochemistry, according to the ESMO definition; all other cases were considered unfavorable. The main endpoint was the progression-free survival (PFS) of first-line CT for advanced disease in all patients and in the unfavorable group.

RESULTS

A total of 56 patients were included, of whom 46 (82%) had unfavorable CUPs. After a median follow-up of 43.9 months, the median overall survival (mOS) was 11.8 months [95% confidence interval (CI) 8.3-15.3 months]. At univariate analysis, the presence of peritoneal metastases and residual tumor after primary surgery were associated with a shorter OS. The median PFS (mPFS) was 6.1 months (95% CI 3.6-8.7 months). In the unfavorable CUP subgroup, the mOS was 12.6 months (95% CI 8.7-16.5 months), the mPFS was 6.1 months (95% CI 3.5-8.9 months) and none of the CT regimens used showed to portend better PFS. The most relevant altered genes included: KRAS (9/29; 31%), BRAF (1/26; 4%), NRAS (1/25; 4%), TP53 (9/23; 39%).

CONCLUSIONS

CUPs with a gastrointestinal profile are characterized by poor prognosis and the absence of biomarker for treatment personalization. No CT regimen was superior in terms of PFS in patients with unfavorable CUPs.

Long-Term Follow-Up of Tamoxifen Treatment and the Use of Imaging in Psammocarcinoma: A Case Report, Review of the Literature and Discussion of Diagnostic and Therapeutic Challenges

Psammocarcinoma (PsC) represents a rare form of low-grade serous tumor of the ovary or peritoneum. Although ovarian cancer generally has a poor prognosis in its late stages, PsC seems to have a more indolent course. We present a patient with a history of unspecific abdominal pain for more than a year, with sudden acute onset of severe inguinal pain. On admission to the hospital, a computed tomography (CT) revealed a pelvic mass of suspected ovarian origin. Radical surgery was attempted but not achieved due to widespread tumor growth. Histopathological evaluation revealed estrogen receptor-positive stage III PsC. Tamoxifen treatment was thus initiated, still maintaining stable disease 10 years later. The patient has undergone extensive radiological work-up, including CT, chest X-ray, 18F-fluoro-deoxy-glucose positron emission tomography (PET)/CT, 99mTc- hydroxymethylene diphosphonate (HDP) bone scintigraphy, 18F-fluoro-thymidine (FLT) PET/CT, Tc-99m depreotide scintigraphy and magnetic resonance imaging. In conclusion, we demonstrate that PsC has characteristic radiological features and different imaging modalities can be suitable in different clinical situations. In contrast to most other ovarian cancers, PsC does not always warrant adjuvant chemotherapy, even in advanced stages. This emphasizes the need for a deeper knowledge of the biological behavior of this rare tumor, to select the optimal treatment strategy.

Case Report: Incidental discovery of primary peritoneal psammocarcinoma

Psammocarcinoma is an uncommon subtype of low-grade serous carcinoma. It is characterized by the presence of extensive psammoma bodies and can have either an ovarian or peritoneal origin. To our knowledge fewer than 30 cases of primary peritoneal psammocarcinoma (PPP) have been reported in the English literature. We report a rare case of  PPP in a 74-year-old female, discovered fortuitously within a laparotomy for gallbladder lithiasis. At laparotomy, multiple nodular implants involving the omentum, the peritoneum and a magma of intestinal loops in the right iliac fossa were noted. A biopsy from nodules was performed. Gross examination showed multiple nodules of different sizes in the fat tissue. Pathologic examination showed massive psammoma bodies representing more than 75% of the tumor. The final diagnosis was psammocarcinoma. Our patient was referred to the gynecologic department for further investigation and to ascertain whether the tumor arose from the ovaries or peritoneum. Hysterectomy, bilateral adnexectomy and omentectomy were performed. Macroscopic examination showed that both ovaries were intact having a normal size. No invasion of ovarian stroma was shown in microscopic examination. The patient died of SARS-CoV-2 (COVID-19) six days after the surgery. PPP is a rare type of  low-grade serous carcinoma. The behavior of this tumor is unclear, and the treatment is not standardized because of its rarity and lack of long-term follow-up. More cases need to be studied for better understanding and improvement of the management protocols.

Contemporary primary treatment of women with stage II-IV low-grade serous ovarian/peritoneal cancer (LGSOC): Determinants of relapse and disease-free survival

OBJECTIVE

The purpose of the present study is to describe a cohort who received contemporary primary treatment for stage II-IV low-grade serous ovarian/peritoneal cancer (LGSOC), including patient characteristics and determinants of relapse and disease-free survival.

METHODS

The study included 99 patients: 1) with pathologically confirmed stage II-IV LGSOC of the ovary or peritoneum, 2) who underwent primary treatment consisting of cytoreductive surgery and either a) platinum/taxane chemotherapy followed by aromatase inhibitor maintenance therapy or b) aromatase inhibitor monotherapy, and 3) for whom there was availability of clinical data. Descriptive statistics were used to characterize clinicodemographic features. Subgroups were compared for PFS and OS. Multivariable Cox regression analyses were performed.

RESULTS

Median PFS for the entire cohort was 56.8 months (95% CI, 41.3-NE), and median OS was 130.7 months (95% CI, 115.0-146.4). Forty-nine of 99 (49.5%) patients have relapsed to date. For these 49 patients, median time from diagnosis to relapse was 29.6 months (95% CI, 24.6-33.1) (range, 5.4-69.1 months). Only 1/49 (2%) patients who relapsed did so >5 years from diagnosis. Fifty (50.0%) patients have not experienced disease progression or relapse. Median follow-up time for these 50 patients is 86.2 months (range, 25.3-169.0). Thirty-three of the 50 (66.0%) have been followed for >5 years from diagnosis. On regression analyses, factors associated with improved patient outcomes-either PFS, OS, or both-included no gross residual disease, normal serum CA 125 at diagnosis, primary peritoneal site, and presence of extensive psammomatous calcifications.

CONCLUSIONS

This is the first report to describe the clinicopathologic features and outcomes of women with stage II-IV LGSOC who received contemporary primary therapy.