Testicular cancer

Anatomy
Lymph nodes:
 -Right testicle goes directly to PA nodes
 -Left testicle drains first to left renal hilum then to PA nodes

Epidemiology
8,000 cases per year, 300 deaths in US
Peak incidence at 15-34 years; non-germinomatous tumors tend to present younger
Worldwide, incidence is going up for unclear reasons

Risk factors
Cryptorchidism
Testicular trauma
Klinefelter's syndrome (Mediastinal germinoma)
Immune suppression
White males
Infertility
Family history
Prior testicular cancer

Pathology
Seminoma
Most common type (more than 50%)
15-30% of seminomas produce B-hCG but all are AFP negative
Spermatocytic subtype of seminoma presents in older men; surgery alone is curative

Non-seminomatous tumors
-Mixed histology is much more common than any of the individual tumors in pure form
-Embryonal tumors: PLAP+; AFP+ in 33%, B-hCG in 20%; about 3% of pure NGGCT
-Yolk sac tumors: elevated AFP; about 2% of pure NGGCT
-Teratoma: normal AFP (5%)
-Choriocarcinoma: elevated B-hCG; aggressive (less than 1%)

Half-lives of tumor markers
AFP: 5 days
B-hCG: 1 day
PLAP: 1 day

Clinical
85% of seminomas are stage I at diagnosis

Workup 
Testicular ultrasound
CT of chest-abdomen-pelvis
Tumor markers, LDH
Fertility counseling
Radical inguinal orchiectomy is diagnostic and therapeutic for both seminoma and non-seminoma
Scrotal violation during surgery is associated with worse local control (3 vs 0.5% local failure rates) but no difference in overall survival
In patients with non-seminomatous histology, retroperitoneal LND is also performed

Prognostic factors
Histology
Tumor size
Rete testis invasion
Site of mets (lung vs. elsewhere)
Tumor marker levels
Mediastinal primaries do worse

Therapy
Stage I seminoma
Fields: PA only vs. PA and pelvic
 -Identical 5-yr RFS (96%)
 -Slightly better pelvic control in PA and pelvic arm (100% vs 98%)
 -Statistically identical OS (99.3 vs 100%)
 -Worse toxicity (nausea, longer delay in sperm count recovery) in PA and pelvic arm

Doses: 20 vs 30Gy
 -Identical 5-year RFS (97%)
 -Statistically identical pelvic control and overall survival
 -Worse toxicity (lethargy, increased time out of work) in 30Gy arm

RT vs. carboplatin
 -Statistically identical RFS (~95%), pelvic control, and overall survival
 -Chemotherapy arm had fewer contralateral testicular tumors

Stage II seminoma
RT recommended for nodes less than 5cm (stage IIA-B)
Stage IIC and higher get chemo as do all non-seminomatous GCTs

Mediastinal seminoma: give higher doses to improve tumor control (40-50Gy??)

Testicular tolerance to radiation
Temporary drop in sperm count at 0.5Gy
Permanent oligospermia at 2Gy
Permanent sterility at 3-4Gy
Endocrine function maintained at least to 30Gy