Small Cell Carcinoma of the Ovary, from the CureRays guide library.

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a very rare, aggressive ovarian cancer of young women driven by loss of the SMARCA4 gene, treated with intensive surgery, chemotherapy, and radiation — and increasingly with targeted and immune approaches.

What it is.

Small cell carcinoma of the ovary, hypercalcemic type — usually abbreviated SCCOHT — is an extremely rare but very aggressive ovarian cancer that strikes young women, with an average age in the early-to-mid twenties. 'Hypercalcemic type' refers to the high blood-calcium level seen in about two-thirds of patients, which can cause nausea, confusion, and kidney problems and usually resolves once the tumor is treated. The defining discovery is genetic: nearly all of these tumors are caused by inactivation of a single gene, SMARCA4 (which makes a protein called BRG1, part of the SWI/SNF complex that helps control which genes are switched on). Because the loss can be inherited, genetic counseling is recommended. Despite the name 'small cell,' it is biologically unrelated to small cell lung cancer. It is rare enough that no single standard of care exists, so treatment combines aggressive surgery, intensive multi-drug chemotherapy, and radiation, often at expert centers and on clinical trials.

How radiation treats it.

Radiation damages the DNA inside cancer cells so they can no longer divide and survive, while healthy cells repair themselves more effectively. In SCCOHT, radiation is used after surgery and chemotherapy to improve control in the pelvis and abdomen, where this aggressive cancer tends to recur, and to treat areas that surgery cannot reach. It is delivered as a series of short, painless daily sessions, uses no radioactive implants, and leaves no radioactivity in your body — so you remain safe to be around family and children throughout.

The ways we can treat it.

Pelvic / whole-abdominal radiation. Carefully planned x-ray radiation treats the pelvis or, in selected cases, the whole abdomen to destroy microscopic cancer left after surgery and chemotherapy.

Intensity-modulated radiation therapy (IMRT). Computer-shaped beams concentrate dose on at-risk areas while sparing the bowel, kidneys, and bladder to reduce side effects.

Stereotactic / palliative radiation. Focused, high-dose radiation can target individual metastases or relieve symptoms such as pain when the disease has spread.

Questions we hear often.

Is this the same as small cell lung cancer? No. Despite sharing the words 'small cell,' SCCOHT is a completely different disease with a different cause (loss of the SMARCA4 gene) and a different treatment. The name only reflects how the cells look under the microscope.

Why am I being offered genetic testing? Because the SMARCA4 change that causes this cancer can be inherited. Genetic testing tells you whether the change is in all your cells (germline) — which has implications for your relatives and for monitoring — or only in the tumor. Either way, it can guide treatment choices.

Why is my blood calcium high, and is it dangerous? About two-thirds of patients have a high calcium level caused by a substance the tumor releases. It can make you feel nauseated or confused and needs prompt treatment, but it usually improves once the cancer is treated. Your team will manage it with fluids and medication.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.