PubMed Health⌕ Search

Biomedical subjects

Jeffrey A Norton

Publications and source records attributed to Jeffrey A Norton.

At least 19 recordsLinked to original sources

Lessons from Coley's Toxin.

The active molecule in Coley's Toxin is not tumor necrosis factor (TNF) or endotoxin (LPS), but interleukin-12 (IL-12). IL-12 holds the key to improved anti-tumor immuns response.

Animals↗

Inhibition of host signal transducer and activator of transcription factor 6 results in cure with cyclophosphamide and interleukin 12 immunotherapy.

BACKGROUND: Interleukin (IL)-12 immunotherapy is highly effective against established immunogenic tumors. However, nonimmunogenic tumors fail to respond to IL-12 therapy. Analysis of tumor rejection of the immunogenic tumors shows that a preexisting antitumor immune response is required for an effective IL-12 response. It is not known whether this lack of a preexisting host antitumor immune response is a limiting factor for the lack of response to IL-12 therapy by nonimmunogenic tumors. METHODS: Experiments were done using the spontaneously arising nonimmunogenic metastatic murine breast 4T1 carcinoma in normal and STAT6 knockout BALB/c mice. RESULTS: 4T1 is nonimmunogenic in normal mice, and established subcutaneous tumors are resistant to immunotherapy with cyclophosphamide (Cy) plus IL-12. However, in STAT6 knockout mice, 4T1 becomes immunogenic, and established 4T1 tumors are eradicated by Cy plus IL-12. Adoptive transfer of spleen cells from normal mice into STAT6 knockout mice before tumor inoculation reduces both the immunogenicity and response to Cy plus IL-12 immunotherapy of 4T1 in the recipient mice. CONCLUSIONS: Cy plus IL-12 immunotherapy can eradicate nonimmunogenic tumors as long as a preexisting immunity is established in the tumor-bearing host. Furthermore, the STAT6 pathway is likely involved in the suppression of the development of host antitumor immunity.

Animals↗

Surgery increases survival in patients with gastrinoma.

OBJECTIVE: To determine whether the routine use of surgical exploration for gastrinoma resection/cure in 160 patients with Zollinger-Ellison syndrome (ZES) altered survival compared with 35 ZES patients who did not undergo surgery. SUMMARY BACKGROUND DATA: The role of routine surgical exploration for resection/cure in patients with ZES has been controversial since the original description of this disease in 1955. This controversy continues today, not only because medical therapy for acid hypersecretion is so effective, but also in large part because no studies have shown an effect of tumor resection on survival. METHODS: Long-term follow-up of 160 ZES patients who underwent routine surgery for gastrinoma/resection/cure was compared with 35 patients who had similar disease but did not undergo surgery for a variety of reasons. All patients had preoperative CT, MRI, ultrasound; if unclear, angiography and somatostatin receptor scintigraphy since 1994 to determine resectability. At surgery, all had the same standard ZES operation. All patients were evaluated yearly with imaging studies and disease activity studies. RESULTS: The 35 nonsurgical patients did not differ from the 160 operated in clinical, laboratory, or tumor imaging results. The 2 groups did not differ in follow-up time since initial evaluation (range, 11.8-12 years). At surgery, 94% had a tumor removed, 51% were cured immediately, and 41% at last follow-up. Significantly more unoperated patients developed liver metastases (29% vs. 5%, P = 0.0002), died of any cause (54 vs. 21%, P = 0.0002), or died a disease-related death (23 vs. 1%, P < 0.00001). Survival plots showed operated patients had a better disease-related survival (P = 0.0012); however, there was no difference in non-disease-related survival. Fifteen-year disease-related survival was 98% for operated and 74% for unoperated (P = 0.0002). CONCLUSIONS: These results demonstrate that routine surgical exploration increases survival in patients with ZES by increasing disease-related survival and decreasing the development of advanced disease. Routine surgical exploration should be performed in ZES patients.

Adult↗

Surgery for gastrinoma and insulinoma in multiple endocrine neoplasia type 1.

The surgical management of pancreatic endocrine tumors in patients with multiple endocrine neoplasia type 1 remains controversial. Gastrinoma and insulinoma are the 2 most common functional pancreatic neuroendocrine tumors in patients with multiple endocrine neoplasia type 1. Gastrinomas cause gastric acid hypersecretion and peptic ulcer disease that are best managed using proton pump inhibitors. Surgery to remove the gastrinoma in patients with multiple endocrine neoplasia type 1 is seldom curative unless a more extensive Whipple pancreaticoduodenectomy is performed. Because the prognosis is excellent, aggressive resections such as a Whipple procedure are only indicated for large, locally metastatic, advanced tumors. Furthermore, surgery to remove imageable tumors that are 2 cm in diameter is associated with excellent outcomes and decreased probability of liver metastases. Because gastrinomas are commonly multiple and most originate in the duodenum and develop lymph node metastases, the duodenum should be opened and all tumors and lymph nodes excised. Insulinomas cause hypoglycemia that results in neuroglycopenic symptoms. Medical management of the hypoglycemia is less effective than that of the gastric acid hypersecretion. Fortunately, the insulinoma is usually clearly identified using routine pancreatic imaging studies. There is a high likelihood of cure when the insulinoma is excised surgically. However, recurrent hypoglycemia may occur, and careful follow-up is indicated.

Biopsy, Needle↗

Characterization of a recurrent germ line mutation of the E-cadherin gene: implications for genetic testing and clinical management.

PURPOSE: To identify germ line CDH1 mutations in hereditary diffuse gastric cancer (HDGC) families and develop guidelines for management of at risk individuals. EXPERIMENTAL DESIGN: We ascertained 31 HDGC previously unreported families, including 10 isolated early-onset diffuse gastric cancer (DGC) cases. Screening for CDH1 germ line mutations was done by denaturing high-performance liquid chromatography and automated DNA sequencing. RESULTS: We identified eight inactivating and one missense CDH1 germ line mutation. The missense mutation conferred in vitro loss of protein function. Two families had the previously described 1003C>T nonsense mutation. Haplotype analysis revealed this to be a recurrent and not a founder mutation. Thirty-six percent (5 of 14) of the families with a documented DGC diagnosed before the age of 50 and other cases of gastric cancer carried CDH1 germ line mutations. Two of 10 isolated cases of DGC in individuals ages <35 years harbored CDH1 germ line mutations. One mutation positive family was ascertained through a family history of lobular breast cancer (LBC) and another through an individual with both DGC and LBC. Occult DGC was identified in five of six prophylactic gastrectomies done on asymptomatic, endoscopically negative 1003C>T mutation carriers. CONCLUSIONS: In addition to families with a strong history of early-onset DGC, CDH1 mutation screening should be offered to isolated cases of DGC in individuals ages <35 years and for families with multiple cases of LBC, with any history of DGC or unspecified GI malignancies. Prophylactic gastrectomy is potentially a lifesaving procedure and clinical breast screening is recommended for asymptomatic mutation carriers.

Adult↗

Endocrine tumours of the gastrointestinal tract. Surgical treatment of neuroendocrine metastases.

Neuroendocrine tumors of the intestinal tract have low malignant potential but can result in decreased survival if they spread to the liver. The estimated 5-year survival of patients with liver metastases from neuroendocrine tumor is only 20%. Further, morbidity related to the Carcinoid Syndrome and other endocrine symptoms may also greatly reduce the quality of life. Treatment options for liver neuroendocrine tumor include long-acting somatostatin receptor antagonists (LAR), inteferon-alpha, chemotherapy and hepatic artery embolisation with and without chemotherapy. Surgical resection is feasible in select patients, but it may result in major morbidity and even mortality. In our series of 18 patients with liver neuroendocrine tumors, there was no operative mortality and acceptable morbidity. All 10 patients with the Carcinoid syndrome had complete amelioration of symptoms and the 5-year actuarial survival was 80%. Aggressive major surgery for liver neuroendocrine tumor metastases can be performed safely with acceptable mortality by experienced surgeons. Results have been similar for patients with gastrinoma and pancreatic neuroendocrine tumors. Surgical resection appears to result in outstanding long-term survival and amelioration of symptoms. It should be the first-line therapy for patients with liver neuroendocrine tumors in whom the tumor can be completely removed.

Carcinoma, Neuroendocrine↗

Surgery and prognosis of duodenal gastrinoma as a duodenal neuroendocrine tumor.

It has become increasingly clear that duodenal gastrinomas are the most common cause of Zollinger-Ellison syndrome (ZES). However, attempts to find these tumors before and during surgery for ZES have had limited success until duodenotomy (opening the duodenum) was described. The routine use of duodenotomy in patients with non-familial gastrinoma increases the number of duodenal tumors found, and the immediate and long-term cure-rate. The increase in cure-rate appears to be secondary to increased detection of small, previously undetectable duodenal gastrinomas. Duodenotomy detects small tumors (<1 cm) in the proximal duodenum. It does not detect more duodenal gastrinomas per patient, nor does it detect tumors in unusual duodenal locations. Duodenotomy decreases the death-rate associated with these tumors. However, it has not affected the rate of development of liver metastases. Duodenotomy is a critical method to find duodenal gastrinomas. It should be routinely performed in all surgery to find and remove gastrinoma for cure of ZES.

Anastomosis, Surgical↗

Surgical treatment and prognosis of gastrinoma.

Zollinger-Ellison syndrome (ZES) is a clinical syndrome with severe peptic ulcer disease and diarrhea caused by gastric acid hypersecretion secondary to a neuroendocrine tumour that secretes excessive amounts of the hormone gastrin (gastrinoma). Gastrinomas occur in a familial and a sporadic form. Patients with gastrinoma in the familial setting of Multiple Endocrine Neoplasia type 1 (MEN-1) are seldom, if ever, cured of Zollinger-Ellison syndrome by the current non-Whipple operations to remove duodenal and pancreatic gastrinoma. Surgery is currently used in these patients to deal with the malignant nature of pancreatic or duodenal neuroendocrine tumours. Malignant potential is best determined by tumour size. Tumours that are greater than 2 cm in size should be excised. In the sporadic setting, cure occurs in a significant proportion of patients (50%) by surgical resection of gastrinoma. Duodenotomy has improved both the tumour detection rate and the cure rate and should be routinely done. Whipple pancreaticoduodenectomy results in the highest probability of cure in both sporadic and MEN-1 gastrinoma patients as it removes the entire gastrinoma triangle. However, the excellent long-term survival of these patients with lesser operations and the increased operative mortality and long-term morbidity of Whipple make its current role unclear until further studies are done.

Female↗

A national comparison of surgical versus percutaneous drainage of pancreatic pseudocysts: 1997-2001.

Case series results indicate that a surgical approach is superior to percutaneous drainage of pancreatic pseudocysts. To determine if this surgical advantage is persistent, national outcomes for both approaches were compared from 1997 through 2001. The National Inpatient Sample, a 20% sample of all nonfederal hospital discharges, was searched for patients who had a pancreatic pseudocyst diagnosis, an ICD-9 diagnosis code 577.2, and an ICD-9 procedure code of 52.01 for percutaneous drainage (PD) or 52.4 and 52.96 for the surgical approaches. Variables were compared by using either t test or chi2 analysis. Confounding variables were controlled for by linear or logistic regression models. No clinically significant demographic, comorbidity, and disease-specific severity-of-illness differences existed between the two groups. Significant differences in complications, length of stay (15+/-15 versus 21+/-22 days, P<0.0001), and inpatient mortality (5.9% versus 2.8%, P<0.0001) favored the surgical approach. In addition, endoscopic retrograde cholangiopancreatography use had a protective effect on mortality (odds ratio, 0.7), whereas percutaneous drainage had an increased risk of mortality (odds ratio, 1.4). This population-based study suggests that surgical drainage of pancreatic pseudocysts, particularly when coupled with use of endoscopic retrograde cholangiopancreatography, leads to decreased complications, length of stay, and mortality in comparison with percutaneous drainage.

Cholangiopancreatography, Endoscopic Retrograde↗

Long-term functionality of cryopreserved parathyroid autografts: a 13-year prospective analysis.

BACKGROUND: The functional results of cryopreserved heterotopic parathyroid autotransplantation (CHPA) are not well defined. The authors evaluated the outcomes of delayed CHPA for the treatment of surgically induced hypoparathyroidism. METHODS: Since November 1991, 448 parathyroid samples from 436 patients were cryopreserved at our institution. Of these, 29 patients underwent 34 CHPA procedures, with placement of 20 to 25 pieces of parathyroid tissue (approximately 50 to 75 mg) into the forearm. Outcomes were determined based on peripheral parathyroid hormone (PTH) levels and, where available, PTH gradients between grafted and nongrafted arms. Graft function results were defined as completely functional (patients with normal PTH and calcium levels off all calcium/vitamin D supplementation), partially functional (normal PTH levels and mild hypocalcemia on calcium supplementation), or nonfunctional (low PTH levels and dependent on calcium/vitamin D supplementation). RESULTS: Of the 29 patients with CHPA, prospective data were available for 26 patients undergoing 30 CHPA procedures (9 patients with MEN 1, 4 with MEN 2A, 1 with MEN 2B, and 12 with sporadic hyperparathyroidism). The mean follow-up interval was 2 years. Twelve of 26 patients (46%) had completely functional grafts, 6 patients (23%) had partially functional grafts, and the remaining 8 patients (31%) had nonfunctional grafts. No patient with CHPA had graft-dependent recurrent hyperparathyroidism. Of the 14 patients (15 autografts) with MEN, 7 patients (50%) had fully functional grafts, and 2 patients (14%) had partially functional grafts. The mean cryopreservation period was 7.9 months (range, 1 week to 22 months) for functional autografts and 15.3 months (range, 2 weeks to 106 months) for nonfunctional autografts (P < .01). CONCLUSIONS: Based on these data and those in previous studies, approximately 60% of delayed, cryopreserved parathyroid autografts are functional. In this study 40% autografts (46% of patients) achieved full competency off supplements. Some patients have evidence of graft function with normal PTH levels but are not normocalcemic. Results were similar for patients with MEN and nonhereditary hyperparathyroidism. The duration of cryopreservation was a significant indicator of graft failure, and no functional autograft was observed beyond 22 months of preservation. CHPA is a useful treatment modality for patients with postoperative hypocalcemia after thyroid or parathyroid surgery, who do not respond to immediate parathyroid autotransplantation.

Adolescent↗

Computed tomography, endoscopic, laparoscopic, and intra-operative sonography for assessing resectability of pancreatic cancer.

Pancreas cancer is the fourth leading cancer killer in adults. Cure of pancreas cancer is dependent on the complete surgical removal of localized tumor. A complete surgical resection is dependent on accurate preoperative and intra-operative imaging of tumor and its relationship to vital structures. Imaging of pancreatic tumors preoperatively and intra-operatively is achieved by pancreatic protocol computed tomography (CT), endoscopic ultrasound (EUS), laparoscopic ultrasound (LUS), and intra-operative ultrasound (IOUS). Multi-detector CT with three-dimensional (3-D) reconstruction of images is the most useful preoperative modality to assess resectability. It has a sensitivity and specificity of 90 and 99%, respectively. It is not observer dependent. The images predict operative findings. EUS and LUS have sensitivities of 77 and 78%, respectively. They both have a very high specificity. Further, EUS has the ability to biopsy tumor and obtain a definitive tissue diagnosis. IOUS is a very sensitive (93%) method to assess tumor resectability during surgery. It adds little time and no morbidity to the operation. It greatly facilitates the intra-operative decision-making. In reality, each of these methods adds some information to help in determining the extent of tumor and the surgeon's ability to remove it. We rely on pancreatic protocol CT with 3-D reconstruction and either EUS or IOUS depending on the tumor location and operability of the tumor and patient. With these modern imaging modalities, it is now possible to avoid major operations that only determine an inoperable tumor. With proper preoperative selection, surgery is able to remove tumor in the majority of patients.

Endoscopy, Digestive System↗

Antitumor immunity induced by dendritic cell-based vaccination is dependent on interferon-gamma and interleukin-12.

BACKGROUND: This study was conducted to determine whether dendritic cells (DCs) pulsed with a tumor cell lysate can effectively vaccinate against tumor cells and to establish which cytokines are necessary. MATERIALS AND METHODS: Each wild-type mouse received two subcutaneous immunizations (days 14 and 7) with either saline, tumor lysate, DCs, or tumor-lysate-pulsed DCs. Gamma-interferon (gamma-IFN), knock-out (KO), and interleukin-12 (IL-12) KO mice were also used in immunizations. A tumor challenge was given at day 0. Splenocytes were assayed for gamma-IFN production. RESULTS: All saline-injected mice (n = 19) and all mice injected with tumor lysate (n = 9) developed tumors. Six of nine mice immunized with DCs alone and 6/24 mice treated with lysate-pulsed DCs developed a tumor. Splenocytes from both the saline- and lysate-immunized groups produced undetectable levels of gamma-IFN, while those from mice immunized with either DCs or pulsed DCs produced high levels of gamma-IFN. Four of five gamma-IFN KO mice developed tumors after immunization with tumor-lysate-pulsed DCs. None of four IL-12 KO mice developed a tumor after immunization with wild-type pulsed DCs and 1/10 wild-type mice developed tumor after immunization with IL-12 KO pulsed DCs. Three of four IL-12 KO mice developed tumors after immunization with IL-12 KO pulsed DCs. CONCLUSIONS: Tumor-lysate-pulsed DCs can initiate an effective antitumor immune response. The presence of gamma-IFN in the host is essential for antitumor protection. In contrast, tumor protection is observed if IL-12 is present in either the host or the DCs.

Animals↗

Gastric carcinoid tumors in multiple endocrine neoplasia-1 patients with Zollinger-Ellison syndrome can be symptomatic, demonstrate aggressive growth, and require surgical treatment.

BACKGROUND: Gastric carcinoid tumors occur in 15% to 50% of patients with multiple endocrine neoplasia-1/Zollinger-Ellison syndrome (MEN-1/ZES) but are thought to be benign. We report 5 patients with MEN-1/ZES with symptomatic, aggressive gastric carcinoid tumors that required surgical procedures. METHODS: This was a retrospective chart review. RESULTS: Each patient had MEN-1/ZES. Each patient had innumerable gastric carcinoid tumors with symptoms. The fasting gastrin level was 47,000 pg/mL (normal, <200 pg/mL); the basal acid output was 79 mEq/hr (n = 3), and the age at surgical exploration was 47 +/- 6 years, with a duration of MEN-1 of 21 +/- 3 years and of ZES of 15 +/- 2 years. All patients had elevated 5-HIAA or serotonin levels. Somatostatin receptor scintigraphy showed increased stomach uptake in 4 patients (80%). Four patients had a total gastrectomy; 4 patients had lymph node metastases removed, and 3 patients had liver metastases resected. One patient who did not have a total gastrectomy had liver carcinoid metastases. CONCLUSIONS: These results demonstrate that gastric carcinoid tumors in patients with longstanding MEN-1/ZES may be symptomatic, aggressive, and metastasize to the liver. With increased long-term medical treatment and life expectancy, these tumors will become an important determinant of survival.

Adult↗

Does the use of routine duodenotomy (DUODX) affect rate of cure, development of liver metastases, or survival in patients with Zollinger-Ellison syndrome?

OBJECTIVE: To determine whether routine use of duodenotomy (DUODX) alters cure rate, survival, or development of liver metastases in 143 patients (162 operations) with Zollinger-Ellison syndrome (ZES) without MEN1. SUMMARY BACKGROUND DATA: DUODX has been shown to increase the detection of duodenal gastrinomas, but it is unknown if it alters rate of cure, liver metastases, or survival. Data from our prospective studies of surgery in ZES allow us to address this issue because DUODX was not performed before 1987, whereas it was routinely done after 1987. METHODS: All patients with sporadic ZES (non-MEN1) undergoing surgery for possible cure without a prior DUODX from November 1980 to June 2003 were included. Patients had preoperative computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound; if unclear, angiography and somatostatin receptor scintigraphy since 1994. At surgery, all had the same standard ZES operation and were assessed immediately postoperatively, at 3 to 6 months, and yearly for cure (fasting gastrin, secretin test. and imaging studies). RESULTS: A DUODX was performed in 79 patients (94 operations), and no DUODX was performed in 64 patients (68 operations), with 10 patients having both (no DUODX, then a DUODX later). Gastrinoma was found in 98% with DUODX compared with 76% with no DUODX (P < 0.00001). Duodenal gastrinomas were found more frequently with DUODX (62% vs. 18%; P < 0.00001), whereas pancreatic, lymph node, and other primary gastrinomas occurred similarly. Six of the 10 patients with 2 operations had a duodenal tumor found with DUODX during a second operation that was missed in the first operation without DUODX. Both the immediate postoperative cure rate (65% vs. 44%; P = 0.010) and long-term cure rate at last follow-up (8.8 +/- 0.4 years; range, 0.1 to 21.5) (52% vs. 26%; P = 0.0012) were significantly greater with a DUODX than without. In patients without pancreatic tumors or liver metastases at surgery, both the rate of developing liver metastases (6% vs. 9.5%) and the disease-related death rate (0% vs. 2%) were low and not significantly different in patients with or without a DUODX. CONCLUSIONS: These results demonstrate that routine use of DUODX increases the short-term and long-term cure rate due to the detection of more duodenal gastrinomas. The rate of development of hepatic metastases and/or disease-related mortality in patients without pancreatic tumors is low, and no effect of DUODX on these parameters was seen. Duodenotomy (DUODX) should be routinely performed during all operations for cure of sporadic ZES.

Duodenal Neoplasms↗

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome.

OBJECTIVE: Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES). SUMMARY BACKGROUND DATA: Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output. METHODS: Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid. RESULTS: Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma. CONCLUSIONS: It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Duodenal Neoplasms↗

High-dose 131I-metaiodobenzylguanidine therapy for 12 patients with malignant pheochromocytoma.

BACKGROUND: 131I-Metaiodobenzylguanidine (131I-MIBG) can be used systemically to treat malignant pheochromocytoma. To improve outcome, the authors used higher levels of activity of 131I-MIBG than previously reported. The authors reported the response rates and toxicity levels in patients with malignant pheochromocytoma or paraganglioma who were treated with high-dose 131I-MIBG. METHODS: Following debulking surgery and stem cell harvest, 12 patients with malignant pheochromocytoma or paraganglioma were treated with 131I-MIBG. Five had received previous external beam radiation and/or chemotherapy. The median single treatment dose was 800 mCi (37 gigabecquerels; range, 386-866 mCi) or 11.5 mCi/kg (range, 5.6-18.3 mCi/kg). The median cumulative dose was 1015 mCi (range, 386-1690 mCi). RESULTS: Three patients had a complete response, two of whom had soft tissue and skeletal metastases. Their median follow-up was 45 months (range, 23-101 months). Seven patients had a partial response (PR), with a median follow-up 43 months (range, 6-47 months). Two patients without a response died with progressive disease (PD) and 2 patients with an initial PR died of PD at 13 and 11 months, respectively. Grade 3 thrombocytopenia occurred after 79% (15 of 19) of treatments had been administered. Grade 3 and 4 neutropenia followed 53% (10 of 19) and 19% (4 of 19) of treatments, respectively. One patient required stem cell infusion, and one developed primary ovarian failure. CONCLUSIONS: The single and cumulative doses of 131I-MIBG were approximately 2-3.5 times higher than those used at other centers. Unlike previous reports, two patients with both skeletal and soft tissue metastases had a complete response. Hematologic toxicity was significant but tolerable. High-dose 131I-MIBG may lead to long-term survival in patients with malignant pheochromocytoma.

3-Iodobenzylguanidine↗

Cure of an established nonimmunogenic tumor, SCC VII, with a novel interleukin 12-based immunotherapy regimen in C3H mice.

OBJECTIVE: To develop a murine model of effective treatment with immunotherapy for established head and neck squamous cell carcinoma. DESIGN: Prospective animal study. Subjects Female C3H mice, 8 to 12 weeks old. INTERVENTIONS: A subcutaneous inoculation of 2 x 10(5) SCC VII cells in C3H mice was established for 7 to 12 days. Tests for concomitant immunity were performed, with and without interleukin 12 modification. Tumors were also tested for responsiveness to interleukin 12 (5 mice) and to cyclophosphamide followed by interleukin 12 (5 mice). SCC VII tumors in 24 mice were treated with interleukin 12 followed by cyclophosphamide and interleukin 12. Five mice with tumors treated with isotonic sodium chloride solution served as controls. Tumors were measured 3 to 4 times weekly, and cure was defined as complete regression of the tumor for at least 60 days. Cured mice were rechallenged with 2 x 10(5) SCC VII cells to verify antitumor immunity. Immunohistochemistry of regressing tumors was performed for CD4+ and CD8+ T cells. RESULTS: Tumor-bearing mice easily developed second tumors when challenged with 2 x 10(5) tumor cells in the opposite flank. However, interleukin 12 treatment provided immunity to second tumors in 8 (100%) of 8 mice when started at day 4 and in 2 (40%) of 5 when treated from day 7. SCC VII did not respond to standard interleukin 12 or cyclophosphamide plus interleukin 12 therapy. Seventy-five percent of animals (18/24) treated with interleukin 12 followed by cyclophosphamide plus interleukin 12 were successfully cured, and all cured mice resisted subsequent challenge with SCC VII. Immunohistochemistry of regressed tumors showed an intense CD4+ and CD8+ infiltrate that was absent in the untreated and nonresponding tumors. CONCLUSIONS: Nonimmunogenic SCC VII is a nonimmunogenic tumor that can be converted into an immunogenic tumor with interleukin 12 treatment. Additional treatment with cyclophosphamide plus interleukin 12 leads to complete regression in 75% of mice.

Adjuvants, Immunologic↗