STAGING OF RECTAL-CANCER - A PROSPECTIVE-STUDY OF DIGITAL EXAMINATIONAND ENDOSONOGRAPHY BEFORE AND AFTER PREOPERATIVE RADIOTHERAPY

Between January 1988 and January 1992, 34 patients with rectal cancer were evaluated both by clinical examination and endosonography before and after pre-operative radiotherapy. Two criteria were correlated wit h histologic findings: confinement to the rectal wall or spread beyond , the presence of mesorectal lymph node involvement. The 32 patients w ho underwent endosonography before radiotherapy were staged as : uT2: 4, uT3: 26, uT4: 2 cases. Fifteen days after irradiation, endosonograp hy showed tumour regression in all cases ; uT stage was different in 1 5 patients, uN stage in 4 cases. Comparison of the pre-operative local invasion beyond the rectal wall with postoperative histopathy reveale d a correlation with : digital examination after radiotherapy in 20 of the 31 patients with palpable tumours ; endosonography before irradia tion in 18 of the 32 staged tumours ; endosonography after irradiation in 25 of the 32 staged tumours. The presence of mesorectal lymph node involvement determined by histologic examination was correlated with the results of endosonography after radiotherapy for 22 of the 32 stag ed tumours. Endosonography provides a good assessment of the tumour st age before irradiation. Since radiotherapy alters endosonographic stag ing of rectal cancer, this staging should be included in survival stud ies.