Hearing that you or a loved one has a diagnosis of ovarian cancer is terrifying. Once the initial shock wears off, you’ll likely have a lot of questions and do some research on your own to answer them. One thing you’ll probably discover: There are actually three overarching types of ovarian cancer. While every person’s experience with cancer will vary, understanding the similarities and differences between these three types might be helpful.
Ovaries are reproductive glands that produce eggs along with the hormones estrogen and progesterone.
The reason there are three types of ovarian cancer lies in the fact that your ovaries contain three main types of cells that can each create tumors, according to the American Cancer Society (ACS). Epithelial cells coat the surface of the ovaries, germ cells create eggs, and stromal cells keep the ovaries together and produce the hormones estrogen and progesterone.
(However, emerging science suggests that some ovarian cancers actually start in the fallopian tubes, which are the structures that connect the ovaries to the uterus. Scientists are continuing to study how exactly this happens.)
Let’s walk through the three types of ovarian cancer in detail.
1. Epithelial ovarian cancer: This begins in that thin layer of tissue that blankets the outside of the ovaries. According to the Mayo Clinic, about 90 percent of ovarian cancers fall into this category. There are a lot of different subtypes of epithelial ovarian cancer, which is a pattern you’ll see with the other kinds of ovarian cancer, too. Serous carcinomas are the most common kind, according to the ACS. Serous refers to serum, the clear liquid portion of blood, the National Cancer Institute explains.
2. Germ cell ovarian cancer: This starts in the egg-producing cells, and it makes up less than 2 percent of ovarian cancers, according to the ACS. However, these cases tend to affect girls and young women. For instance, dysgerminoma, the most common ovarian germ cell cancer, typically develops in women in their teens and 20s. Another kind of ovarian germ cell cancer called immature teratoma usually happens in girls younger than 18.
“We don’t really know why [these cancers mainly affect young women and girls]” Stephen Rubin, M.D., chief of the Division of Gynecologic Oncology at Fox Chase Cancer Center, tells SELF. “They do arise from the germ cells in the ovaries which give rise to the eggs. It may be that these cells are more numerous and active in younger women, but that’s speculation.”
3. Stromal ovarian cancer: Official numbers vary, but this seems to make up about 1 percent of ovarian cancers. It starts in the ovarian tissue that contains hormone-generating cells and is usually diagnosed at an earlier stage than other ovarian cancers, the Mayo Clinic says. “[These tumors] tend to sit in the ovary and grow for a long period of time without spreading,” Dr. Rubin says. “It gives us more time to find them.”
Cancerous stromal growths, which include granulosa cell tumors (the most common type), granulosa-theca tumors, and Sertoli-Leydig cell tumors, can all secrete the reproductive hormone estrogen. This is important because it can translate into some of the more noticeable symptoms of ovarian cancer, which is often able to fly under the radar.
Before we delve into ovarian cancer symptoms, it’s important to be really clear about this: Not all ovarian growths (or growths in general) are cancerous.
Although epithelial, germ cell, and stromal tumors can lead to three distinct and eponymous types of ovarian cancer, they can also all cause tumors that aren’t cancerous. For instance, epithelial cystadenomas are benign growths that can be filled with a watery or mucous-based liquid, according to the Mayo Clinic. And germ cell growths are usually benign tumors called mature teratomas, the ACS explains. These can contain a bunch of different types of tissue including—gulp—hair, skin, and teeth.
There are some typical symptoms of ovarian cancer, but the frustrating thing is that they’re so vague.
“In general, ovarian cancers don’t hurt and don’t produce enough noticeable symptoms unless [they’ve grown to a] large size,” Dr. Rubin says. With that in mind, these are the usual symptoms of ovarian cancer, according to the Mayo Clinic. As you’ll see, they can all be due to a wide range of things that often have nothing to do with cancer:
- Abdominal bloating or swelling
- Feeling full quickly when you eat
- Unexplained weight loss
- Pelvic discomfort
- Changes in your bowel habits, like constipation
- Needing to pee a lot
Epithelial ovarian cancers (the ones that make up 90 percent of all ovarian cancers) are most likely to have these standard but nebulous symptoms, Robert Wenham, M.D., chair of gynecologic oncology at Moffitt Cancer Center, tells SELF. The other two less common forms are at least more likely to cause more attention-grabbing symptoms.
Some germ cell cancers, specifically dysgerminomas, can grow to a large size before being diagnosed, which can leave a person with abdominal pain, Dr. Rubin says. They can also cause irregular bleeding. “These tumors are highly vascular and may rupture and bleed,” he says.
Abnormal vaginal bleeding is actually the most common symptom of stromal ovarian cancer, the ACS says. This is due to the aforementioned excess estrogen this cancer can create. On the flip side, stromal tumors can also make hormones like testosterone, the ACS says. That can cause a person’s periods to stop and lead them to grow facial and body hair. Either way, if the tumor starts to bleed, it can cause severe abdominal pain seemingly out of nowhere, the ACS explains.
The added estrogen from stromal ovarian cancer can also cause breast tenderness, Shannon Westin, M.D., an associate professor in the department of gynecologic oncology and reproductive medicine at M.D. Anderson Cancer Center, tells SELF, along with breast development before puberty.
Treatment for ovarian cancer varies based on the stage, grade, and type a person is at when they’re diagnosed.
You’re probably already familiar with staging, which is essentially figuring out how much a cancer has spread. So, let’s talk about grades of ovarian cancer. Depending on how much the tissue in a cancerous tumor looks like regular tissue, it will receive a grade, the ACS explains. The higher the grade, the less the tumor has in common with normal tissue. The tumor will also get a type (beyond the general types of ovarian cancer discussed above) based on how quickly the cells grow and how well they might respond to chemotherapy. Type 1 tumors grow more slowly and cause fewer symptoms, the ACS says, while type II do the opposite.
Doctors can have their suspicions that someone has ovarian cancer, they really won’t know all of these details until they get a pathology report, which typically comes after surgery, Dr. Wenham says, hence why surgery is a mainstay of ovarian cancer treatment.
The extent of the surgery depends on how much the cancer has spread, the Mayo Clinic explains. Remember, malignant and borderline malignant tumors all have the capacity to metastasize.
If the cancer is limited to one ovary, surgery may only require removing that gland and its accompanying fallopian tube, according to the Mayo Clinic. This can be a good fit if the patient still hopes to physically carry a pregnancy in the future. If the cancer has spread to both ovaries, those will need to be removed, as will the fallopian tubes. But leaving the uterus behind means a person could still theoretically carry a pregnancy via frozen embryos, frozen eggs, or donor eggs. However, if the cancer is also affecting the uterus (or if the person with cancer would rather preemptively have their uterus removed than preserve the chance to physically carry a pregnancy), that organ may also be taken out along with the ovaries and fallopian tubes, the Mayo Clinic explains. Nearby lymph nodes and a piece of fatty abdominal tissue called the omentum can also contain cancerous cells at this point, so they will likely come out as well.
Beyond that, doctors may recommend chemotherapy to kill cancer cells that remain after surgery. “Rarely, radiation may be used,” Dr. Wenham says. Radiation relies upon strong rays or particles of energy to target those cancer cells, but chemotherapy tends to be more effective for ovarian cancer.
Again, since everyone’s cancer experience can be so different, this is only meant to be an informative primer. If you or a loved one is diagnosed with ovarian cancer, Dr. Westin stresses the importance of being treated by a specialist if at all possible, particularly one at a major cancer center that deals with ovarian cancer often. They should be able to explain the specifics of the situation and, hopefully, determine which treatment has the best chance of success.