Tissue Sample Collection From Patients With Soft Tissue Sarcoma of the Arms, Hands, Legs, or Feet Treated on Clinial Trial CRUK-VORTEX

DISEASE CHARACTERISTICS: * Histologically confirmed soft tissue sarcoma * Receiving treatment on clinical trial CRUK-VORTEX * Underwent surgery to remove the tumor no more than 3 months ago PATIENT CHARACTERISTICS: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 3 months after completion of study treatment * No other major medical illness that would preclude study treatment * No other prior or concurrent malignancy except adequately treated nonmelanoma carcinoma of the skin or in situ carcinoma of the cervix PRIOR CONCURRENT THERAPY: * No prior radiotherapy to the local site * No prior neoadjuvant or adjuvant chemotherapy