Is Transvaginal Core Needle Biopsy A Safe Method in Diagnosis of Ovarian Cancer?

1. Background

Cytoreductive surgery followed by chemotherapy has been the standard approach in all stages of ovarian cancer. It seems impossible to achieve optimal debulking in many cases of highly advanced stages of this disease (1). Few cycles of neoadjuvant chemotherapy and subsequent interval debulking surgery in new clinical trials are preferable optional management for these patients. This strategy led to fewer surgeries and possibility of more chance for optimal operation (2). Although it is necessary to obtain definite diagnosis of ovarian carcinoma, needle aspiration of malignant cells in ascetic fluid is an acceptable method, but tissue diagnosis is preferable. However, the risk of un-treatable abdominal wall metastasis in both procedures is reported (3). In order to obtain acceptable accurate tissue biopsy and to avoid the dissemination of tumor in needle insertion site, transvaginal ultrasound-guided core needle biopsy appears to be a suitable method with low risk of iatrogenic intra-peritoneal dissemination (4). The transvaginal ultrasound-guided biopsy was first reported by Volpi et al. in 1991, performed on 18 suspected cases with ovarian cancer (5). Kitayama et al. obtained tissue biopsy under guided transvaginal ultrasonography in patients with frozen pelvis due to severe peritoneal adhesion of ovarian cancer. They were able to obtain accurate tissue diagnosis through transvaginal in almost half of the patients with advanced ovarian cancer (6). It seems that, in recent years, neoadjuvant chemotherapy followed by debulking surgery is a front-line opinion in treatment of advanced stage of ovarian cancer. Prior to commencing chemotherapy, tissue diagnosis is required. The aim of this study is to evaluate transvaginal core needle biopsy as a safe method for diagnosis of ovarian cancer.

2. Methods

This clinical trial study was performed on patients who were referred to gynecology oncology department of Ghaem Hospital, Mashhad University of Medical Sciences during 2014 to 2015. This study was approved by the ethics committee of Mashhad University of Medical Sciences.

The inclusion criteria included: 1, provisional clinical presentation of advanced stage of ovarian cancer (Stage III c stage IV); 2, features of ultrasound or CT- scan compatible with malignancy; 3, elevated CA - 125; 4, impossible optimal cytoreductive surgery without neoadjuvant chemotherapy; 5, not acceptable methods for sampling, such as peripheral lymphadenopathy, and 6, deep pelvic palpable tumor and safely accessible to sampling through recto vaginal examination. The evaluated variables included the complaint of patients, patients' age, performance Status, the character of masses on sonography, the level of tumor marker, the histology of tumor, the accuracy of tissue biopsy, and needle site metastases. An informed consent was obtained from each participant prior to study entrance. Initially, pain medication by 800 mg gelofen began for all patients. After recto vaginal examination, transvaginal sonography guided core needle biopsy in standard fashion was performed by a 16-gauge needle biopsy (Soja -Machi, Japan). The duration of biopsy procedure was about 10 minutes. During the first 2 hours of sampling, the monitoring of vital signs was performed every half hour and, then, every hour up to 4 hours; then, the patients were discharged. All patients underwent cytoreductive surgery after 3 to 6 courses of neoadjuvant chemotherapy. To reduce the risk of invasion in needle site, during surgery, we removed more upper vaginal walls.

3. Results

A total of 12 women with a presumptive diagnosis of stage III c or IV ovarian cancer entered to the study and were evaluated. The demographic characteristics of the patients are shown in Table 1; the mean age of the patients was 56.75 years. The average level of marker CA - 125 was 1837. Papillary serous carcinoma was reported in the majority of samples. Adequate sample was obtained by transvaginal core needle biopsy, and cancer diagnosis was confirmed in all cases, correlated with final pathology report after surgery. The best result was that 2/3 of patients (stage III c or IV) operated optimal debulking surgery.

There was no case of excessive hemorrhage or hemodynamic instability. There was mild discomfort during the procedure in all patients, which settled as soon as the procedure was completed, and no patients except 1 requested analgesic. In all patients with cancer diagnosis at first biopsy, the pathology was consistent with the pathology obtained after surgery.

4. Discussion

According to the results of this study, transvaginal core needle biopsy under the guide of sonography was a suitable approach in the diagnosis of advanced ovarian cancer suspected non-optimal surgery, and 100% success rate without serious complication was found. In a study conducted by Volpi et al., one false-negative histological evaluation and one inadequate sample were without major complications (3, 5). Obviously, we recommend this approach only for the advanced stages of ovarian cancer to avoid tumor spillage by any diagnostic sampling method of ovarian carcinoma. In suspected cases with ovarian cancer candidate to neoadjuvant chemotherapy, an accurate tissue diagnosis is mandatory. Since cytology is not enough accurate as histology, it is better to obtain tissue biopsy as possible. To avoid the risk of iatrogenic abdominal wall metastasis, transvaginal core needle biopsy under the guide of sonography is a useful alternative method. Moreover, the risk of needle site metastasis is reduced by eliminating most of the upper vaginal wall during cytoreductive surgery (7, 8). We must note that the success rate of this procedure depends on the experienced operator, the depth of the biopsy target, the deflection tumor, encapsulates pelvic mass, and appropriate cases (7). A 100% success rate was obtained in our procedure due to skillful team. Another benefit of this method is that it is easier to perform than other exploratory procedures; thus, it can be alternative tissue sampling by laparoscopy or laparotomy and avoids general anesthesia. In addition, this procedure is associated with possible needle site metastasis. However, it permits applying optimal surgery when highly invasive surgery is anticipated. Likewise, less surgical time duration and more effective tumor debunking due to tumor shrinkage after neo-adjuvant chemotherapy are other advantages of this method (8). The median survival rate in patients with ovarian cancer in stage III c, IV, who achieved optimally debulked and adjuvant chemotherapy, was about 66 months. Half of the recurrences in these patients occurred during first 2 years after the end of treatment. Since the study took about 1 year, we did not have any recurrence at this time. Therefore, based on what was mentioned above, sonographic guided core needle biopsy led to the pathologic diagnosis of malignant ovarian masses with high accuracy and safety rate and omits the risk of needle site metastasis in suitable selected cases.

We did not have any limitations in this study and all patients had good cooperation with our team. Transvaginal core needle biopsy of ovarian mass under the guide of sonography is an acceptable and preferable approach in distinguishing ovarian cancer cases, which require neoadjuvant chemotherapy.

Since the overall follow up time of this study is short, more time is needed to evaluate the accurate benefit of this approach on the disease free survival in advanced ovarian cancer.