Testicular Cancer

CS IA and IB

Three options, with surveillance preferred (recommended by both 2019 AUA and 2010 CUA, with adjuvant therapy as an alternative); long-term survival approaches 100% with each:

Option	Detail
Surveillance (preferred)	Orchiectomy alone cures 80–85% of CS I seminoma
Adjuvant radiotherapy	20 Gy to the para-aortic region
Adjuvant chemotherapy	Single-agent carboplatin × 1 cycle

If adjuvant therapy is chosen, CUA prefers radiotherapy over chemotherapy, EAU recommends against radiotherapy, and SWONTECA uses radiotherapy only when chemotherapy is unsuitable.

Surveillance

Protocols vary (no consensus): history/physical and cross-sectional abdominal (± pelvic) imaging every 4–6 months for years 1–2, then every 6–12 months in years 3–5; chest imaging and markers as clinically indicated. Surveillance is harder than in NSGCT because markers have limited utility for detecting seminoma relapse. Risk factors for relapse: tumour size >4 cm and rete testis invasion. Relapses are fully restaged and treated by TNM-S status.

Adjuvant Radiotherapy

Delivered as a dog-leg field (retroperitoneum + ipsilateral pelvis) or para-aortic field:

• Dog-leg — in-field recurrence <1% (most recurrences in thorax and left supraclavicular fossa, nearly all cured with first-line chemotherapy); persistent oligospermia in 8%. Advantage: no serial follow-up CT needed.
• Para-aortic — smaller field and dose, but requires serial follow-up CT. An RCT found it non-inferior to dog-leg in CS I seminoma.

Adjuvant Chemotherapy

Carboplatin is superior to cisplatin for CS I seminoma; serial follow-up CT is required.

CS IIA and IIB

About 15–20% of seminoma is CS II at diagnosis, and 70% of those are IIA/IIB.

• CS IIA — CUA: dog-leg radiotherapy (25–35 Gy) preferred over first-line chemotherapy (BEP×3 or EP×4); AUA: radiotherapy or chemotherapy.
• CS IIB — CUA: radiation or chemotherapy by bulk/location, with first-line chemotherapy (good-risk BEP×3 or EP×4) for bulky (>3 cm) and/or multifocal retroperitoneal disease; AUA: node ≤3 cm → radiotherapy or chemotherapy, node >3 cm → chemotherapy.
• Routine surveillance CT is unnecessary after complete resolution.
• RPLND is an emerging option: the SEMS phase II trial (Daneshmand, 2023) treated 55 men with isolated 1–3 cm retroperitoneal nodes by open RPLND, achieving 2-year relapse-free survival of 81% (86% cN1 vs 64% cN2) and 2-year overall survival of 100%.

CS IIC and III

Regimen and cycles follow the IGCCCG classification — good-risk: BEP×3 or EP×4; intermediate-risk: BEP×4.

Residual Masses & Relapse

After chemotherapy, 60–80% have a radiologic residual mass, but histology is overwhelmingly necrosis (90%) vs viable malignancy (10%) — far more favourable than NSGCT (necrosis 40%, viable 15%, teratoma 45%). Most need no treatment: spontaneous resolution occurs in 50–60% (median 13–18 months), and post-chemotherapy surgery is technically difficult (desmoplastic reaction, higher morbidity). Teratoma/malignant transformation is much less of a concern than in NSGCT.

• Residual >3 cm → FDG-PET: positive → post-chemotherapy surgery; negative → observation.
• Residual <3 cm → observation.
• Post-chemotherapy radiotherapy has no role.

After radiotherapy, biopsy and confirm histology before acting — seminoma rarely transforms into NSGCT elements (consider this when metastatic seminoma fails conventional therapy). Open or robotic/laparoscopic biopsy of a para-aortic mass is acceptable if CT-guided biopsy is unfeasible or non-diagnostic, and RPLND should not be performed without histologic confirmation of NSGCT.

Relapse:

• Chemo-naïve — relapse on surveillance → primary radiotherapy; patients previously treated with radiotherapy (or surveillance relapse with bulky >3 cm retroperitoneal masses and systemic relapse) → first-line chemotherapy by IGCCCG. Salvage rates approach 100%.
• Early relapse after chemotherapy → salvage chemotherapy. Consider teratoma at the relapse site in advanced seminoma; with normal markers, biopsy before starting second-line chemotherapy.

Self-Test

1. What is the preferred management of CS I seminoma, and the two alternatives? Surveillance is preferred; alternatives are adjuvant para-aortic radiotherapy (20 Gy) or single-agent carboplatin × 1.

2. What two features predict relapse of CS I seminoma on surveillance? Tumour size >4 cm and rete testis invasion.

3. How does the histology of post-chemotherapy residual masses differ between seminoma and NSGCT? Seminoma: ~90% necrosis, 10% viable. NSGCT: ~40% necrosis, 15% viable, 45% teratoma.

4. How is a residual seminoma mass managed by size after chemotherapy?

3 cm → FDG-PET (positive → surgery, negative → observe); <3 cm → observe. Post-chemotherapy radiotherapy has no role.

5. Before performing RPLND for a post-radiotherapy para-aortic mass in seminoma, what is required? Histologic confirmation of NSGCT — RPLND should not be done on imaging alone.