– rapid-onset opioid – ras gene – rasburicase – rattlesnake root – ravuconazole – rebeccamycin – recombinant tissue plasminogen activator – reconstructive surgeon – reconstructive surgery – recurrent cancer – Red blood cell – Reed–Sternberg cell – reflux – refractory cancer – regional cancer – regional chemotherapy – regional enteritis – regional lymph node – regional lymph node dissection – rehabilitation specialist – relative survival rate – relaxation technique – remission induction therapy – remote brachytherapy – renal cell cancer – renal collecting tubule – renal glomerulus – renal tubular acidosis – retinoblastoma – retinoid – retinol – retinyl palmitate – retroperitoneal – retropubic prostatectomy – retrospective cohort study – retrospective study – retroviral vector – retrovirus – RevM10 gene – rhabdoid tumor – rhabdomyosarcoma – rhizoxin – ribavirin – ribonucleotide reductase inhibitor – rifampin – risedronate – ritonavir – rituximab – RK-0202 – RMP-7 – RNA – Ro 31-7453 – Ro 50-3821 – rofecoxib – rosiglitazone – RPI.4610 – RPR 109881A – RSR13 – RSV S S-1 – S-phase fraction – safingol – salpingo-oophorectomy – salvage therapy – samarium 153 – saponin – saquinavir mesylate – sarCNU – sarcoma – sarcosinamide nitrosourea – sargramostim – satraplatin – SC-70935 – SCH 54031 – SCH 66336 – SCH-58500 – Schiller test – Schwann cell – schwannoma – scintimammography – scleroderma – screening mammogram – Scutellaria barbata – SDX-102 – SDX-105 – second primary cancer – second-line therapy – second-look surgery – secondary cancer – sedoxantrone trihydrochloride – segmental cystectomy – segmental mastectomy – selective estrogen receptor modulator – selective serotonin reuptake inhibitor – sella turcica – semaxanib – seminal vesicle biopsy – seminoma – semiparasitic – semustine – senile keratosis – sentinel lymph node – sentinel lymph node biopsy – sentinel lymph node mapping – seocalcitol – SERM – serotonin – sertraline – serum albumin – serum glutamate pyruvate transaminase – Serum glutamic oxaloacetic transaminase – serum tumor marker test – sesquiterpene lactone – sestamibi breast imaging – severe myelosuppression – Sézary syndrome – SGN-00101 – SGN-15 – SGOT – SGPT – sham therapy – shave biopsy – Sho-saiko-to – sialic acid – sialyl Tn-KLH – side-to-end coloanal anastomosis – sideropenic dysphagia – sigmoidoscope – sigmoidoscopy – signal transduction inhibitor – signet ring cell carcinoma – SIL – sildenafil – Silybum marianum – silymarin – simple mastectomy – simple nephrectomy – single blind study – single-photon emission computed tomography – siplizumab