Liquid Biopsy: A Newer, Less Invasive Way to Detect and Monitor Cancer

Any scrotal swelling should first be evaluated with ultrasound, which will show a testicular mass or enlargement, but there is no test that gives a confirmed diagnosis before surgery, that only comes after radical orchiectomy. Of 100 patients presenting with a testicular swelling, roughly 80 to 90 percent will have cancer and about 10 percent tuberculosis, so for the large majority a biopsy is avoided, since it risks spreading the cancer, in favour of going directly to orchiectomy. Tumour markers such as AFP and beta-hCG, elevated in seminoma and yolk-sac tumours, can support the ultrasound finding, but the standard recommendation regardless of marker levels is orchiectomy rather than biopsy.

PSA is not specific for prostate cancer at all, no tumour marker is specific for any single cancer. An elevated PSA in a patient with a prostatic mass could reflect BPH or cancer, and can rise even after a digital rectal exam or ejaculation. Very high values, such as over 100, are more suggestive of cancer, so if PSA is extremely elevated yet the biopsy shows only BPH, the biopsy may simply have missed the cancerous core, which does happen. In such suspicious cases, a gallium-68 PSMA PET scan, highly specific for prostate cancer, can help confirm or rule out malignancy before treating for BPH alone.

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.

It tests a blood sample for circulating tumour cells and cell-free DNA released by a cancer, without needing to sample the tumour directly.

Yes. If there is no clear indication for chemotherapy after surgery, testing for circulating tumour cells can reveal whether cancer cells remain, informing whether to add chemotherapy.

Around six months after treatment finishes, a liquid biopsy showing no circulating tumour cells is reassuring against recurrence, while a positive result can flag a recurrence early.