Seminoma Management
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Direct answer
Seminoma is the radio- and chemo-sensitive germ cell tumour of men aged 30-40, presenting as a painless testicular mass with a pure seminoma histology after radical inguinal orchidectomy and, crucially, a normal alpha-fetoprotein. Stage I disease is managed by surveillance (the preferred option for compliant men), a single dose of carboplatin (area under the curve 7) or para-aortic radiotherapy about 20 Gy, all with excellent cure rates around 98-100 per cent. Stage IIA-IIB disease is treated with radiotherapy to the para-aortic and ipsilateral iliac fields or chemotherapy, while bulky (IIC-III) seminoma receives BEP or EP chemotherapy, with residual masses handled by observation, radiotherapy or surgery depending on size, because seminoma is exquisitely radiosensitive.
What you must remember
- Pure seminoma never raises AFP; if AFP is elevated, treat as non-seminomatous regardless of histology. Beta-hCG is raised in only a minority and does not change the label.
- Stage I options: surveillance (preferred in reliable patients), one cycle of carboplatin AUC 7, or radiotherapy 20 Gy in 10 fractions to the para-aortic strip — each yields nearly identical cancer-specific survival.
- Adjuvant carboplatin (single dose, AUC 7) lowers relapse from roughly 15-20 per cent to under 5 per cent, with the main advantage of reducing contralateral testicular tumours and avoiding radiation.
- Classic radiotherapy field ("dog-leg" for node-positive stages) covers para-aortic and ipsilateral iliac nodes; late costs include secondary malignancies and cardiovascular disease, which drove the shift to surveillance and carboplatin.
- Stage IIA/B: radiotherapy (about 30-36 Gy) to para-aortic and ipsilateral iliac nodes or cisplatin-based chemotherapy (BEP ×3 or EP ×4); stage IIC and above — chemotherapy by IGCCCG risk, and seminoma has no poor-risk category.
- Residual mass after chemotherapy: a mass under about 3 cm is observed (most are fibrosis); larger masses need PET-CT assessment, and surgery is a last resort because seminomatous tissue is friable and surgery carries morbidity.
- After orchidectomy alone, relapse in stage I seminoma is mostly para-aortic within the first two years, so surveillance CT schedules are demanding — the trade-off for avoiding treatment.
How to work through a case
A 36-year-old man undergoes radical inguinal orchidectomy for a 4 cm tumour; histology is classic seminoma with no vessel invasion, markers normalise (AFP was never raised), and staging CT chest-abdomen-pelvis is clear — stage I. Walk the consultation. Step 1: establish that it truly is stage I pure seminoma — normal post-operative markers and negative imaging, plus review of the histology for trophoblastic elements. Step 2: lay out the three options with numbers: surveillance with CT at defined intervals for about five years, relapsing in 15-20 per cent but almost all salvaged; single-dose carboplatin AUC 7, dropping relapse below 5 per cent with a day-unit visit; para-aortic radiotherapy, equally effective but carrying the late second-cancer and cardiac penalty that modern practice tries to avoid. Step 3: choose by patient reality — a man travelling every month cannot keep surveillance visits; shared decision-making and documentation are the standard. Step 4: if he had presented with a 3 cm para-aortic node (stage IIB), the options shift to dog-leg radiotherapy about 30-36 Gy or BEP ×3, both effective. Step 5: after chemotherapy for bulky disease, re-image; a residual mass under 3 cm is observed, while larger masses are assessed by PET-CT before any further treatment — most residual seminoma masses are fibrosis.
High-yield viva angles
The examiner opens with "AFP is raised and histology says seminoma — what do you do?" — treat as NSGCT; this single sentence separates the prepared from the rest. The second angle is the trade-off conversation: surveillance avoids treatment but demands visits; carboplatin is one day of treatment with modest late risk; radiotherapy carries the best-documented late toxicity — there is no wrong answer, only an unjustified one. Third, radiation fields: para-aortic alone for stage I versus the dog-leg field when nodes are involved — and always shield the remaining testis. Fourth, "Why not RPLND for seminoma?" — because seminoma is radiosensitive and the retroperitoneal tissue after chemotherapy is dangerous to operate; primary retroperitoneal lymph node dissection has no role in seminoma, unlike NSGCT. Fifth, the PET-CT nuance: it is useful in seminoma residual masses (unlike NSGCT, where PET is not routinely used post-chemotherapy for teratoma) — a discriminating, frequently examined fact.
Frequently asked questions
What are the treatment options for stage I seminoma?
Surveillance (preferred for adherent patients), one cycle of adjuvant carboplatin at area under the curve 7, or para-aortic radiotherapy of about 20 Gy — all with near-identical excellent survival.
Why is an elevated AFP incompatible with pure seminoma?
Seminoma cells do not synthesise AFP; an elevated AFP implies yolk sac or embryonal elements, reclassifying the tumour as non-seminomatous and managing it on that pathway.
Which radiotherapy field is used for stage IIA seminoma?
A "dog-leg" field covering para-aortic and ipsilateral iliac lymph nodes to about 30-36 Gy, with contralateral testicular shielding to protect remaining spermatogenesis.
How are residual masses after chemotherapy for seminoma managed?
Masses under about 3 cm are observed; larger masses are assessed by PET-CT, and surgery is reserved for growing or FDG-avid disease because most residual tissue is fibrosis.
Is retroperitoneal lymph node dissection performed in seminoma?
Not as primary therapy — seminoma responds to radiotherapy and cisplatin chemotherapy, and post-chemotherapy retroperitoneal surgery is difficult and rarely required.