A 72-year-old Japanese woman visited her doctor due to a complaint of frequent urination. She had a history of breast-conserving surgery, radiation therapy, and tamoxifen treatment for left breast cancer at the age of 47. She had no family history that indicated a hereditary predisposition to breast or ovarian cancer. The doctor ordered an MRI scan, which identified a uterine fibroid in the back wall of the uterus and a cyst near the right ovary. Both of them lacked any signs of malignancy.
Her blood tests showed normal levels of cancer-related markers (CA125, CA19-9, and CEA). To alleviate her frequent urination issues, she underwent an abdominal simple total hysterectomy along with a bilateral oophoro-salpingectomy. This surgery aimed to relieve pressure caused by the uterine fibroid.
Moreover, examination before surgery did not reveal any abnormalities in the right fallopian tube. However, after a pathological examination, doctors discovered that the right fallopian tube contained a small tumour. This was approximately 5 mm in size. This tumour showed various growth patterns and characteristics indicative of high-grade serous carcinoma. The tumour cells displayed significant nuclear abnormalities and a high rate of cell division. Immunostaining tests further confirmed the diagnosis of high-grade serous carcinoma.
Fallopian Tube Cancer Diagnosis
Due to this diagnosis of primary fallopian tube cancer, doctors referred the patient to a different hospital for specialized treatment of her condition.
The patient’s levels of CA125, CA19-9, and CEA—markers associated with cancer—were all normal when tested at our hospital. A follow-up CT scan also showed no signs of enlarged lymph nodes or distant spread of the disease. Our preliminary diagnosis indicated that the patient likely had primary cancer in her right fallopian tube. This condition was suspected to be at an early stage according to the International Federation of Gynecology and Obstetrics (FIGO) staging, possibly stage IA. To confirm the diagnosis and determine the extent of the cancer, doctors performed a comprehensive surgical procedure known as a staging laparotomy. This involved examining the pelvic and para-aortic lymph nodes, conducting a partial omentectomy, obtaining peritoneal biopsies, and analyzing ascites (fluid in the abdomen). Fortunately, doctors found no visible abnormalities during this surgical exploration, and the patient’s recovery after the surgery was uneventful.
However, a detailed examination of the tissue samples obtained during the surgery revealed a small metastatic tumour. It measured less than 10 mm, in one of the para-aortic lymph nodes. This metastatic tumour shared similar characteristics with the original tumour in the right fallopian tube. It exhibited solid growth patterns, psammoma bodies, and pronounced nuclear abnormalities. Laboratory tests further confirmed this was a metastasis of high-grade serous carcinoma from the right fallopian tube.
Notably, the patient’s ascites, omentum, peritoneum, and pelvic lymph nodes showed no signs of metastasis. Following these findings, the doctors diagnosed the patient with stage IIIA1(i) right fallopian tube cancer, specifically high-grade serous carcinoma (HGSC). To address the cancer, the patient received six courses of a chemotherapy regimen consisting of paclitaxel and carboplatin. These were administered intravenously in a dense dose.
Hereditary Breast and Ovarian Cancer
Given the patient’s history of both fallopian tube cancer and previous breast cancer, doctors strongly suspected that she might have Hereditary Breast and Ovarian Cancer (HBOC). Initially hesitant about genetic testing, the patient eventually underwent a BRCA test. This test revealed a genetic mutation in the BRCA2 gene. This information was crucial as it guided treatment choices and surveillance plans. Based on the genetic results, the patient underwent the recommended chemotherapy. Subsequently, doctors put her on a maintenance regimen involving olaparib for two years. She remained disease-free for 18 months after her surgery.
Risk-reducing salpingo-oophorectomy (RRSO) has proven to be a highly effective measure for individuals with hereditary breast and ovarian cancer syndromes. Recent analysis of RRSO has revealed that high-grade serous carcinoma (HGSC), is a common type of ovarian cancer. It originates from the epithelium of the fallopian tube rather than the ovary itself. Genetic abnormalities in the fallopian tube epithelium are linked to the progression from serous tubal intraepithelial carcinoma (STIC), a precursor lesion, to HGSC. Thus, removing the fallopian tubes (salpingectomy) is considered a preventative measure against ovarian cancer. This bilateral salpingectomy is becoming more common in gynecological surgeries, even in the absence of observable lesions.
Several studies have revealed that hidden cancers can be discovered in the fallopian tubes after postoperative pathological examination. For instance, the occurrence of occult cancers in fallopian tubes during gynecological surgery for benign tumours has been documented at frequencies of 1.44% for endometrial cancer. Moreover, it is 0.60% for cervical cancer and 0.19% for ovarian cancer. The rate of finding hidden ovarian cancer was reported as 0.04% in those under 40 years old. 0.15% in those aged 40–54, and 0.47% in those aged 55 and older. Therefore, while the likelihood of occult ovarian cancer increases with age, most cases are detected early. Fallopian tube cancer, being rarer than ovarian cancer, is even less likely to be identified as occult cancer.
Guidelines from the National Comprehensive Cancer Network (NCCN) recommend considering surgical staging or adjuvant chemotherapy for patients newly diagnosed with ovarian cancer. Surgical staging involves a thorough examination to determine the extent of the disease, followed by treatment based on the findings. If staging surgery is not chosen, adjuvant chemotherapy is typically advised due to the potential for residual disease. However, more recent studies have also highlighted the efficacy of maintenance therapy with PARP inhibitors, especially for patients with a BRCA mutation, after adjuvant chemotherapy.
In our case, a reoperation was considered feasible, leading us to perform a staging laparotomy. Despite no observable enlarged lymph nodes during preoperative and intraoperative assessments, a postoperative pathological examination revealed a solitary metastasis in the para-aortic lymph nodes.
For HBOC patients, RRSO is crucial in preventing ovarian cancer development. Studies have found that hidden cancers, including intraepithelial carcinomas, can be discovered in the ovaries and fallopian tubes after RRSO at rates of 7.9%, 2.6%, and 2.6% in different studies. Following the NCCN guidelines for HBOC patients, RRSO is recommended by age 35–40 for BRCA1 mutation carriers and by age 40–45 for BRCA2 mutation carriers. This case highlights the importance of early RRSO for HBOC patients, as the histological type of ovarian cancer, especially HGSC, often leads to rapid metastasis. A timely RRSO could have prevented fallopian tube cancer development in our patient, and early action might contribute to an improved prognosis.