Why are we still talking about ‘ovarian’ cancer?

What if the common cancer that everyone refers to as ovarian cancer actually starts elsewhere in the body and only later takes up residence in the ovaries? That scenario, which is slowly emerging as the reality of this disease, could change how it is treated and prevented.

We made that shocking discovery as we were researching our new books on women’s and men’s cancers. Seventy-five percent of the most deadly form of so-called ovarian cancer actually arises in the fallopian tubes. These tubes capture unfertilized eggs released by the ovary and transport them to the uterus.

As we describe in “Reimagining Women’s Cancers,” the new name for “ovarian” cancer is pelvic serous carcinoma, or PSC. It starts in the fallopian tubes and then spreads to the ovaries and other pelvic organs.

This new, potentially radical concept was uncovered in 2007, in large part due to women who carry the BRCA1 or BRCA2 mutations. These genetic changes greatly increase a woman’s risk for breast and ovarian cancer. Women who carry these genes often undergo prophylactic removal of both fallopian tubes and both ovaries (a procedure known as bilateral salpingo-oophorectomy) in an effort to eliminate the source of cancer — which was thought to be the ovaries.

When pathologists carefully studied the tissues removed from women with BRCA1 or BRCA2 mutations, they found precancerous conditions or early cancers in up to 17 percent of them. The real surprise was the finding that these cancers and pre-cancers were always seen in the fallopian tubes, never in the ovaries.

Over the next seven years, this finding was repeatedly confirmed by medical researchers and was also extended to non-hereditary “ovarian” cancer. Gynecologists started to take action on this paradigm shift in 2013.

In 2015, the same year that actress Angelina Jolie had her ovaries removed to prevent BRCA1-related cancer, the Society of Gynecologic Oncology published new recommendations that included removing just the fallopian tubes in women who had completed childbearing in order to prevent what they were still calling ovarian cancer. Because the ovaries are the source of the hormone estrogen, which helps controls the menstrual cycle, keeping them in place helps prevent premature menopause, which is associated with heart disease, osteoporosis, neurological and psychiatric diseases, and an overall increase in the risk of dying prematurely.

The shift from believing that ovarian cancer begins in the ovaries to the understanding that it starts in the fallopian tube has critical implications for the development of new ways to screen for, prevent, and treat the disease.

Given this new scientific understanding, it is now incorrect and misleading to refer to the majority — and most deadly form — of pelvic serous cancers as ovarian cancer. In an age of precision medicine, we hope that doctors, administrators, insurance companies, policy makers, and advocacy groups will define and explain these conditions for the public with the appropriate accuracy women and their loved ones deserve.

Beyond semantics, however, there is real harm in misleading women with an outdated term. It impairs awareness of new possibilities for prevention and treatment while also hindering promising new avenues of research. New approaches to a redefined disease could dramatically improve screening and early detection.

The TP53 cancer gene, for example, is found in the vast majority of pelvic serous cancers. Someday it might be possible to detect it early through so-called liquid biopsies of blood or cervical secretions.

This new understanding of the disease formerly known as ovarian cancer and its consequences may not only reduce the risk of developing it, but may also eliminate premature menopause and preserve the ability to bear a child in women at high risk for it, who now might need to have only their fallopian tubes removed, and not their ovaries.

Mark S. Boguski, MD, is senior vice president for precision medicine at Inspirata, Inc. and a member of the US National Academy of Medicine. Michele R. Berman, MD, is a medical journalist. Together they create Celebrity Diagnosis: Teachable Moments in Medicine.