Gynaecological Cancers: Ovarian, Cervical and Endometrial

Ovarian cancer: the silent disease and the platinum backbone

Ovarian cancer earns its nickname: "the disease that whispers." Its early symptoms are vague — bloating, mild abdominal discomfort, feeling full quickly — so most women are diagnosed only when the disease is already advanced and has spread across the peritoneal cavity. The cornerstone of treatment is surgery to remove as much tumour as possible (cytoreduction / debulking), followed by chemotherapy. The workhorse regimen pairs a platinum agent — usually carboplatin — with a taxane — usually paclitaxel. The platinum drug damages tumour DNA by forming cross-links; the taxane freezes the cell's microtubule skeleton so it cannot divide. (The mechanics of each live in the Platinum-agents and Microtubule-targeting chapters; here they simply arrive as the reliable first-line pair.)

Ovarian cancer usually responds well to that first platinum course — and then, often, it comes back. How the relapse is treated hinges on a single, powerful idea: how long the disease stayed away after the last platinum dose. If it relapses six months or more later, it is called PLATINUM-SENSITIVE and can be re-treated with platinum. If it returns sooner, it is PLATINUM-RESISTANT, and oncologists switch to non-platinum drugs instead. This platinum-sensitive versus platinum-resistant distinction is one of the most important decision points in all of gynaecological oncology.

The clever weapon: PARP inhibitors and synthetic lethality

The biggest recent advance in ovarian cancer is a class of drugs given not to shrink the tumour outright, but as MAINTENANCE — a tablet taken after chemotherapy to keep the cancer suppressed and delay its return. These are the PARP inhibitors (olaparib, niraparib). Their logic is elegant. A cell has two main ways to repair broken DNA. PARP handles one kind of repair; the BRCA genes handle another (homologous recombination). A tumour that already has a broken BRCA gene has lost one repair system. Block PARP with a drug, and you knock out the backup too — the cell now has no way to mend its DNA and dies. A healthy cell, with its BRCA intact, survives because it still has that pathway. Killing a cell only when TWO systems fail together is called synthetic lethality.

Alongside chemotherapy, some women also receive bevacizumab, an antibody that blocks VEGF — the signal tumours use to grow their own blood supply. Starve the tumour of new vessels and you slow its growth and its spread of fluid (ascites). Bevacizumab is a monoclonal antibody, so its full story sits in the Monoclonal-antibodies chapter; in ovarian cancer it is added to chemotherapy and sometimes continued as maintenance.

Cervical cancer: the cancer you can vaccinate against

Almost every cervical cancer starts with a virus. Persistent infection with high-risk types of the human papillomavirus (HPV) drives the great majority of cases — which makes cervical cancer unusual: it is largely PREVENTABLE. Two tools do the preventing. The first is the HPV vaccine, given to adolescents before exposure; it teaches the immune system to block the virus so the infection — and the cancer it would eventually cause — never gets started. (Vaccines as a class belong to the Antimicrobials/vaccines section; here the point is that a vaccine can pre-empt a cancer.) The second is screening — the Pap smear and HPV testing — which catches pre-cancerous changes early enough to remove them before they ever become invasive. Together, vaccination and screening are among the greatest cancer-prevention successes in medicine.

When cervical cancer is already advanced, the pharmacology shifts to treatment. Locally advanced disease is treated with chemoradiation — radiotherapy given together with cisplatin, which acts as a radiosensitizer (it makes the tumour cells more vulnerable to radiation) as well as a chemotherapy agent. For metastatic or recurrent disease, bevacizumab (anti-VEGF, again) is added to chemotherapy, and immunotherapy has become central: pembrolizumab, a checkpoint inhibitor, releases the brakes on the immune system so it can attack the tumour — and it works especially well when the tumour expresses the marker PD-L1.

Endometrial cancer: hormones, and the immunotherapy surprise

Endometrial (uterine) cancer — cancer of the womb's lining — is the most common gynaecological cancer in high-income countries, and it is often hormone-related: chronic exposure to oestrogen unopposed by progesterone stimulates the endometrium to grow. Most cases are caught early, when they present with abnormal bleeding, and early disease is cured surgically (hysterectomy). The pharmacology matters most when the disease is advanced or recurrent. Chemotherapy again leans on the familiar carboplatin + paclitaxel pair. But the striking recent development is immunotherapy: a large subset of endometrial tumours are MSI-high / mismatch-repair-deficient (dMMR), meaning they have lost the machinery that fixes small DNA copying errors and so accumulate thousands of mutations. Those mutations make the tumour look highly "foreign" to the immune system — and highly responsive to checkpoint inhibitors, sometimes combined with the kinase inhibitor lenvatinib.

Because endometrial cancer is so often hormone-driven, hormones can also treat it. In selected patients with low-grade, hormone-receptor-positive tumours — for example a young woman who wishes to preserve fertility — progestins (synthetic progesterone) are used to oppose oestrogen's growth signal and shrink or stabilize the disease. This links back to the Endocrine sex-hormones section, where progesterone's actions are covered in full; here it is simply a gentle, oral option for the right, carefully chosen case.