Staging for OVFTP malignancies

Cancers of the ovary, fallopian tube and peritoneum may be more effectively treated if the links between them are recognised and explored.

This is one of the conclusions of a new round-up of evidence published as part of FIGO's updated Cancer Report 2018, which includes revised guidelines as to how these particular types of cancer should be staged.

Cancer staging always involves information about where tumours are located, the cell type, size, grade and whether or not it has spread to nearby lymph nodes or other parts of the body.

However, FIGO’s Gynecologic Oncology Committee recently revised the staging process of ovarian cancer to incorporate ovarian, fallopian tube and peritoneal cancer into the same system.

Prior to this, it had been presumed that cancer in the fallopian tubes was rare, but more recent histologic, molecular, and genetic evidence has shown that as many as 80 per cent of tumours that had been classified as originating in the ovaries or peritoneum may actually have developed in the fallopian tubes.

This new data made it clear that high-grade cancers of the ovaries, fallopian tubes and peritoneum are more closely linked than previously thought and so should be considered collectively.

Indeed, the peritoneum is actually the most common site for dissemination of ovarian and fallopian tube cancers, and malignancies that appear to have come primarily from the peritoneum may involve the ovaries and fallopian tubes secondarily.

The updated, revised FIGO staging system combines the classification for ovarian, fallopian tube and peritoneum cancer and is based on findings made mainly through surgical exploration, since operative findings allow doctors to determine the precise histologic diagnosis, stage and prognosis of the patient.

Under the new system, Stage IC is now split into three categories:

• IC1 - Surgical spill
• IC2 - Capsule ruptured before surgery/tumour on ovarian of fallopian tube surface
• IC3 - Malignant cells in ascites or peritoneal washings

A revision of Stage IIIC is also included in the updated staging, which includes information on spread to the retroperitoneal lymph nodes alone, without intraperitoneal dissemination.

This category is now subdivided into:

• IIIA1(i) - Metastasis less than 10mm in greatest dimension
• IIIA1(ii) - Metastasis greater than 10mm in greatest dimension.

Stage IIIA2 now refers to "microscopic extrapelvic peritoneal involvement with or without positive retroperitoneal lymph node" metastasis.

FIGO continues to endorse the World Health Organization histologic typing of epithelial ovarian tumours and fallopian tube and peritoneal neoplasia as follows:

• Serous tumours
• Mucinous tumours
• Endrometrioid tumours
• Clear cell tumours
• Brenner tumours
• Undifferentiated carcinomas
• Mixed epithelial tumours
• Peritoneal carcinoma or serous carcinoma of undesignated site (where the ovaries and fallopian tubes appear to be incidentally involved and not the primary origin).

FIGO also continues to support the fact that a thorough staging laparotomy is an important part of early management and systemic treatment including chemotherapy, hormone therapy and targeted cancer drugs.

However, it is vital that doctors have a common language to accurately describe the size and spread of cancers and apply standard treatment guidelines, as well as compare treatment results between research studies and identify appropriate clinical trials.

That is why it is important to regularly review and update data and guidelines as our experts have done here.

Better understanding and updating staging could make a real difference to patient treatment and, ultimately, survival rates for cancers of the ovaries, fallopian tubes and peritoneum going forward.

Find out more in FIGO's updated Cancer Report 2018.