Brenda Sickle-Santanello

Radioimmunoguided surgery using monoclonal antibody

The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery.

Radioimmunoguided surgery using the monoclonal antibody B72.3 in colorectal tumors

The authors have developed a hand-held gamma-detecting probe (GDP) for intraoperative use that improves the sensitivity of external radioimmunodetection. Radiolabeled monoclonal antibody (MAb) B72.3 was injected in six patients with primary colorectal cancer and 31 patients with recurrent colorectal cancer an average of 16 days preoperatively. The GDP localized the MAb B72.3 in 83 percent of sites. The technique, known as a radioimmunoguided surgery (RIGSTM) system did not alter the surgical procedure in patients with primary colorectal cancer but did alter the approach in 26 percent (8/31) of patients with recurrent colorectal cancer. Two patients avoided unnecessary liver resections and two underwent extraabdominal approaches to document their disease. The RIGS system may influence the short-term morbidity and mortality of surgery for colorectal cancer. Larger series and longer follow-up are needed to determine whether the RIGS system confers a survival advantage to the patient with colorectal cancer.

Multiple reoperations in recurrent colorectal carcinoma. An analysis of morbidity, mortality, and survival

Fifty‐eight patients in an existing prospective study were evaluated to determine if multiple reoperations for recurrent colorectal carcinoma extended survival. All patients had at least three major operative procedures. The median survival from first, second, third, fourth, and fifth recurrence was 29.9, 17.3, 16, 12.3, and 7.2 months, respectively. The median postoperative hospital stay was 11 days, with a range of 1 to 96 days. The major complication rate was 17%. Twenty‐one patients are still alive 19 to 140 months from diagnosis (mean, 50.3 months), 9 to 125 months from the first recurrence (mean, 31.1 months), and 5 to 109 months (mean, 22 months) from the second recurrence. Eleven patients have no evidence of disease. Reoperation for recurrent colorectal carcinoma can be done with acceptable morbidity and mortality and an increase in survival.

Use of polar solvents in chemoprevention of 1,2‐dimethylhydrazine‐induced colon cancer

To examine the effect of the polar solvents on 1,2‐dimethylhydrazine(DMH)‐induced colon cancer, 100 male Sprague‐Dawley rats were randomly allocated to a control and three treatment groups. Treated animals received N‐methylformamide (NMF), dimethylsulfoxide (DMSO), or methylsulfonylmethane (MSM) added to drinking water 1 week before carcinogen injections commenced and for the duration of the experiment. Primary tumors were detected by serial laparotomy under ether anesthesia performed at 2‐month intervals and commencing after carcinogen injections had been completed. The average time to tumor onset was significantly delayed in rats receiving NMF and MSM (P = 0.0141 and 0.0398 respectively, Mantel‐Haenszel test). In addition, fewer poorly differentiated tumors were noted in treatment groups. No weight loss or toxicity was observed. These findings demonstrate that the polar solvents significantly reduce the latent period to tumor onset in DMH‐induced colon cancer and indicate the need to further investigate such compounds as chemopreventive agents.

Follow-up on flow cytometric DNA analysis of squamous cell carcinoma of the tongue

Preliminary data from this institution suggested that flow cytometric DNA analysis was an objective prognostic indicator in archival localized squamous cell carcinoma of the tongue. Technical improvements were made, including analysis of tumor, normal tissue, and a combination of the two; standardized cursor placement; mathematic determination of tetraploid populations; and development of a statistical analysis. A larger number of patients (60) with this disease were reviewed. DNA content was related to disease-free survival, local recurrence, regional metastasis, and incidence of second primary tumors. There was no significant difference between aneuploid and diploid tumors with respect to the variables analyzed. We believe these technical improvements will enhance flow cytometric DNA analysis of paraffin-embedded tissues. However, in this retrospective review of localized squamous cell carcinoma of the tongue, DNA analysis was not a valuable prognostic indicator. Only prospective studies will address this issue.

Needle localization of mammographically detected lesions in perspective

Needle localization of mammographically detected lesions has been shown to detect early breast cancer. One hundred seven patients who underwent needle localized biopsy from June 1977 to September 1985 were reviewed. Eighty percent of the biopsies were benign and 20 percent were cancers (22 patients). In patients undergoing modified radical mastectomy, 80 percent of the axillary specimens were node-negative. During the same 8 year period, 570 breast cancers were diagnosed. Needle localization was responsible for only 4 percent of all cancers found. Though needle localization represents an advance in the detection of early breast cancer, the majority of cancers are found by physical examination. The importance of routine examination by a physician and self-breast examination remains paramount.

Variation in recognition of recurrent colonic cancer by different CEA assays

Forty-six patients were followed with serial CEA determinations by two CEA assays after curative resection of a primary or recurrent colonic cancer. Thirteen have had a histologically proven recurrence, of which only six (46 percent) were predicted by both assays, while seven (54 percent) were predicted by one assay only. The assays appear complementary in indicating tumor recurrence, and preliminary findings suggest that it may be beneficial to follow patients with more than one CEA assay after resection of a primary or recurrent colonic cancer.