Risk of local recurrence after rectal surgery is nationally 8% after curative surgery to 5%. Local recurrence rate after curative surgery varies between 3-7% in the variety of regions in the country. It is well known that the surgical technique total mesorectal excision (TME) has led to improved prognosis after rectal cancer surgery. TME surgery is difficult to perform and different factors affect the quality of TME preparations. Injuries in mesorectal fascia has been reported in up to 20% of patients who underwent TME surgery and most surgeons agree that this may be important for recurrences. However, it is unclear to what extent a damaged mesorectal fascia can be related to a worsening of prognosis in patients with rectal cancer.

Adjuvant oncological treatment in form of chemotherapy after surgery, is offers patients with unfavorable tumors based on the pathological examination. Patients with favorable tumors (less advanced) are not offered chemotherapy, even if the surgical technique was not optimal, ie. that there is damage in the mesorectal fascia, as evidence for this is lacking.

The presence of intraperitoneal cancer cells (IPC) is related to histopathological tumor stage of colorectal cancer. Incidence of IPC of intraperitoneal tumors (rectal cancer patients with tumors below the peritoneal reflection) is unclear.

Assessment of IPC status with cytology and immunohistochemistry is technically easy and could after TME surgery identify those patients who have an increased risk of tumor recurrence. In a positive IPC status, the patient would possibly benefit from either postoperative radiotherapy if the patient did not receive preoperative therapy, or postoperative oncological chemotherapy.

Tumour cells may be lysed in sterile water, and some surgeons rinse the abdominal cavity and the bowel distally to the tumour. Neither rinsing the abdomen or rectum in colorectal cancer is routinely occurring and the clinical benefit has not been established. The value of rinsing the abdomen after TME-surgery could also be studied by IPC status.

The study hypothesis is that the IPC status is dependent on the surgical quality of the specimen after TME-surgery in rectal cancer patients, and its presence leads to increased risk of local recurrence.

Inclusion Criteria:

• rectal cancer patients that are going to be operated with bowel resection
• control patients (10 patients) - patients with different conditions that are going to be operated.

Exclusion Criteria:

• none

40 patients with rectal cancer and 10 patients without rectal cancer that are operated.