Junichi Ikeda

Effects of a combination of cyclophosphamide and human recombinant interleukin 2 on pulmonary metastasis after the surgical removal of a 3-methylcholanthrene-induced primary tumor in autochthonous mice.

We have investigated the therapeutic effects of a combination of cyclophosphamide (CY, 150 mg/kg, iv) and human recombinant interleukin 2 (IL‐2, 5 × 104 JU/day, ip for 5 days) on autochthonous tumors induced in mice by 3‐methylcholanthrene. The initial treatment was carried out when the tumor had reached 8 to 10 mm in diameter. Twenty‐eight out of 35 mice (80%) died of local recurrence and pulmonary metastasis of tumor cells within 53 × 40 days (mean survival time, MST × SD) after the surgical removal of the primary tumor. When these mice were treated with both CY and IL‐2 following the operation (Op), only 10 out of 20 mice (50%) died of recurrence and metastasis. The survival rate, however, was not improved by CY chemotherapy alone or IL‐2 immnnotherapy alone, although each provided a prolongation of the MST. Natural killer cell and LAK precursor cell activities in the spleen cells from the treated mice were found to be restored by IL‐2 alone or CY + IL‐2, whereas they were suppressed by CY alone. These findings reveal that the restoration of the antitumor activity of spleen cells does not provide an improved therapeutic effect by itself and that IL‐2 immunotherapy requires the associated effect of CY chemotherapy to achieve an improved therapeutic effect.

TWO OPERATED CASES OF PERFORETED METASTATIC TUMOR OF THE SMALL INTESTINE FROM LUNG CANCER

Two operated cases of perforated peritonitis due to metastatic lesion in the small intestine from lung cancer are described. Case 1: A 75-year-old man underwent left upper lobectomy for poorly differentiated adenocarcinoma of the lung. On the 7th postoperative day the patient developed abdominal pain. At emergency laparpotomy, a mass with perforation was found in the jejunum. Partial excision of the intestine including perforated lesion was performed. Case 2: A 64-year-old man was seen at the hospital because of abrupt onset of abdominal pain 42 months after operation for lung cancer (moderately differentiated squamous cell carcinoma). Examination indicated perforated peritonitis. At emergency laparotomy, two masses were found in the jejunum, and were resected. Histologically, the pulmonary and intestinal lesion were identical. Both case 1 and case 2 were lost 53 and 51 days after laparotomy respectively. Metastasis to the small intestine from lung cancer is rare, but we should take care of the abdominal symptoms when we follow up the patients with lung cancer.