Tumour Markers: What They Can and Cannot Tell You

Core needle biopsy is sufficient for breast cancer, and there is no need for excisional biopsy in most cases. For a small tumour such as a fibroadenoma, excisional biopsy is an option, but core needle biopsy is equally effective, and if the mass proves benign, surgery can be avoided altogether.

Unfortunately there is no specific genetic mutation identified for uterine fibroids and no targeted drug role for them, since fibroids are benign tumours, not cancers. Treatment options remain limited to hormonal therapy or surgery.

Targeted therapy's main advantage is that it is mostly oral medication without the classic side effects of chemotherapy, so it remains a reasonable option even in poor performance status, though this depends on the specific drug and its side-effect profile rather than being a blanket rule. Two cases illustrate this: a metastatic lung cancer patient with brain metastases who was bedridden with severe headache and vomiting, and a metastatic breast cancer patient with cerebellar metastasis causing incoordination, both showed marked improvement on targeted therapy despite their poor baseline state. Overall, more patients in poor performance status can be treated with targeted therapy than with chemotherapy, since chemotherapy is often not feasible in a very poor clinical state.

FNAC (fine needle aspiration cytology) involves inserting a needle into a tumour or fluid-filled cyst and aspirating fluid along with a few detached cells for slide evaluation under a microscope; sensitivity is low since so few cells come through, and a pathologist can typically only confirm abnormal cells are present, not the exact cancer subtype needed for hormone receptor and HER2 testing. Core biopsy uses a biopsy gun that removes a cylindrical piece of tissue roughly a centimetre long, providing enough tissue for full histopathological and genetic workup, which is why core biopsy, not FNAC, is preferred whenever cancer is suspected.

Breast cancer is broadly split into three types: hormone receptor positive, HER2 positive, and triple negative. The diagnostic procedure itself does not change based on subtype: a biopsy is still required, with mammography used only for initial evaluation. IHC testing on the biopsy sample determines ER, PR and HER2 status; if all three come back negative, the cancer is classed as triple negative, a more aggressive subtype that is harder to treat once it reaches stage four.

Supporting a decision to go straight to surgery when biopsy is deliberately avoided, and tracking whether a cancer is responding to treatment or recurring during follow-up.

No. PSA can rise with benign prostatic enlargement, after a digital rectal exam, or even after ejaculation, so it is not specific to prostate cancer on its own.

A gallium-68 PSMA PET scan, which is specific for prostate cancer, can help resolve the discrepancy rather than assuming the high PSA was a false alarm.