Cells mediating specific in vitro cytotoxicity. II. Probable autonomy of thymus-processed lymphocytes (T cells) for the killing of allogeneic target cells.

In order to investigate whether only T cells are involved in a cell-mediated cytotoxic system in vitro, we tested the cytotoxicity of immune killing cell populations as deprived as possible of B cells. Educated thymus cells, immune spleen cells purified by filtration through a column of beads coated with antimouse Ig antiserum, and finally educated thymus cells further purified by filtration through such a column fully retained their specific cytotoxic activity. This very strongly suggests that only T cells are involved in the killing of target cells by allogeneic immune cells in vitro, in this system. Receptor-bearing cells involved in killing in the present system are thus very probably T cells. This point was further strengthened by the demonstration of specific adsorption, on the relevant monolayers, of each of the three above mentioned killing cell populations.

Stereotactic body radiotherapy of primary and metastatic renal lesions for patients with only one functioning kidney.

BACKGROUND: About 2% of patients with a carcinoma in one kidney develop either metastases or a new primary tumor in the contralateral kidney. Often, renal cancers progress rapidly at peripheral sites and a metastasis to the second kidney may not be the patient's main problem. However, when an initial renal cancer is more indolent yet spreads to the formerly unaffected kidney or a new primary tumor forms there, local treatment may be needed. Stereotactic body radiotherapy (SBRT) has been demonstrated as a valuable treatment option for tumors that cause local symptoms. Presented here is a retrospective analysis of patients in whom SBRT was used to control primary or metastatic renal disease. PATIENTS AND METHODS: Seven patients with a mean age of 64 (44-76) were treated for metastases from a malignant kidney to its contralateral counterpart. Dose/fractionation schedules varied between 10 Gy x 3 and 10 Gy x 4 depending on target location and size, given within one week. Follow-up times for patients who remained alive were 12, 52 and 66 months and for those who subsequently died were 10, 16, 49 and 70 months. RESULTS: Local control, defined as radiologically stable disease or partial/complete response, was obtained in six of these seven patients and regained after retreatment in the one patient whose lesion progressed. Side effects were generally mild, and in five of the seven patients, kidney function remained unaffected after treatment. In two patients, the creatinine levels remained moderately elevated at approximately 160 micromol/L post treatment. At no time was dialysis required. CONCLUSION: These results indicate that SBRT is a valuable alternative to surgery and other options for patients with metastases from a cancer-bearing kidney to the remaining kidney and provides local tumor control with satisfactory kidney function.

Thymidylate synthase expression: an independent prognostic factor for local recurrence, distant metastasis, disease-free and overall survival in rectal cancer.

Several studies have suggested that the intratumoral level of thymidylate synthase (TS) in colorectal tumors correlates with survival. We have studied the correlation between TS expression in primary rectal cancer and locoregional recurrence, distant metastases, and survival. TS enzyme levels were evaluated immunohistochemically using the specific monoclonal antibody TS 106 in paraffin-embedded tumors from 243 patients who had undergone primary surgery for rectal cancer during the years 1980-1993. All patients were included in prospective randomized trials aimed at determining the clinical value of a short preoperative course of local radiation therapy (five doses of 5 Gy each). With a median follow-up of 94 months (range, 43-202 months), it was observed by multivariate analysis that Dukes' stage and TS expression were independent prognostic markers of locoregional recurrence (P < 0.001 and P = 0.038, respectively) distant metastasis (P < 0.001 and P = 0.011, respectively) disease-free survival (P < 0.001 and 0.014, respectively), and overall survival (P < 0.001 and 0.020, respectively). By multivariate analysis, preoperative irradiation therapy showed a borderline improvement in locoregional recurrence (P = 0.051). No other factors, such as age, sex, differentiation of the tumor, or p53 expression, were noted to be independent prognostic factors for clinical outcome in these patients. We concluded that the intratumoral expression of TS in primary rectal cancer is an independent prognostic factor for locoregional recurrence, distant metastases, disease-free survival, and overall survival. Patients with low intratumoral TS expression had a significantly better outcome than those with high TS expression.

Immunohistochemically detected thymidylate synthase in colorectal cancer: an independent prognostic factor of survival.

Intratumoral thymidylate synthase (TS) expression and M(r) 53,000 phosphoprotein (p53) overexpression were studied immunohistochemically in sections from stored paraffin-embedded primary colorectal cancers in 70 patients who had undergone surgery during the years 1987-1990. These cancers were classified according to Dukes' stage A-D, using monoclonal antibodies TS 106 and DO-7. In patients with Dukes' stage A-C tumors, univariate analyses showed that there was a significant correlation (P = 0.048) between disease-free survival and TS expression and between TS expression and time to death with colorectal cancer (P = 0.038). In patients with Dukes' stage A-D tumors, overall survival was correlated to TS expression (P = 0.015), Dukes' stage (P < 0.001), and level of tumor differentiation (P = 0.044) but not to p53 overexpression. Patients with low intratumoral TS expression survived significantly longer than patients with high expression. Cox multivariate analysis showed that Dukes' stage (P < 0.001) and TS expression (P = 0.043) could independently serve as prognostic factors for time to death with colorectal cancer in patients with Dukes' stage A-D tumors.

Immunohistochemical determination of thymidylate synthase in colorectal cancer--methodological studies.

With the aid of specific monoclonal antibodies, an immunohistochemical technique has recently been developed for the detection of intratumoral thymidylate synthase (TS). This technique can be applied to paraffin-embedded material suitable for retrospective studies. In order to examine this technique further, the TS enzyme activity of lysates from frozen-stored colorectal cancer (CRC) specimens were compared with their immunohistochemical TS staining intensity (arbitrarily graded from 0 to 3). A statistically significant correlation between these two methods on a total of 25 tumour specimens (P < 0.001) was observed. The staining intensity in different areas of 48 paraffin-embedded CRCs was examined. Sixty-seven per cent of the tumours were homogeneously stained (either grades 0-1 or 2-3), 33% showed a heterogeneity in TS staining. Increased TS expression correlated with more advanced Dukes' stage (P < 0.001). It is concluded that TS immunostaining intensity reflects TS enzyme activity in colorectal tumours and is well suited for paraffin-embedded material. The TS immunostaining pattern is heterogeneous in up to one-third of the tumours.

Indomethacin modulation of monocyte cytokine release following pelvic irradiation for cancer.

Pelvic irradiation for urogenital cancer reduced monocyte release of tumour necrosis factor alpha (TNF-alpha). Addition of indomethacin to monocyte cultures increased TNF-alpha production after but not before irradiation. E. coli lipopolysaccharide (LPS) increased TNF-alpha release before as well as after radiation therapy and addition of indomethacin to LPS-stimulated monocytes further increased TNF-alpha production following radiotherapy. Spontaneous interleukin-1 (IL-1) release was increased in the cancer patients and was not significantly affected by radiation therapy. LPS increased IL-1 release before as well as after irradiation, but indomethacin did not further change IL-1 secretion. These findings suggest that prostaglandins differentially regulate TNF-alpha and IL-1 release. Administration of cyclo-oxygenase inhibitors during radiation therapy might increase TNF-alpha release in vivo and thereby enhance the host defence against tumours.

Different dose regimens of 5-fluorouracil and interferon-alpha in patients with metastatic colorectal carcinoma.

Three different 5-fluorouracil (5-FU)-interferon-alpha-2b (IFN)-containing regimens were designed for treatment of patients with advanced colorectal cancer. 87 patients with a Karnofsky index > or = 70 were included in three sequential non-randomised phase II trials. Regimen A consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by weekly 1-h intravenous infusions until week 8. IFN (5 MU) was given subcutaneously on days 1, 3 and 5 followed by injections (9 MU) every second day until week 8. The cycle was then repeated. Regimen B consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by 5-min intravenous injections on days 12 and 19. IFN (3 MU) was given subcutaneously on days 1-5 followed by injections (5 MU) on days 11-13 and 18-20. The cycle was repeated every fourth week. Regimen C consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5. IFN (3 MU) was given subcutaneously on days 1-5. The cycle was repeated every third week. The objective response rates (complete response (CR) and partial response (PR)) after approximately 4 months of therapy or longer were as follows: regimen A (n = 27) 22% (2 CR, 4 PR), regimen B (n = 33) 42% (4 CR, 10 PR) and regimen C (n = 27) 22% (1 CR, 5 PR). The corresponding response figures for previously untreated patients were regimen A 50%, regimen B 64% and regimen C 38%. Response durations varied from a few weeks up to 142 + weeks. Toxicities were generally mild and reversible, and the treatments were convenient for the patients and cost effective since the 5-day infusions could be given by a portable pump without hospitalisation. Our results are in agreement with those of others showing that 5-FU/IFN combinations can be highly effective in advanced colorectal cancer, and that a number of factors such as doses, dose intensities, infusion rates and timing of the two drugs may be crucial for the anti-tumour activity of this drug combination.

Changes of the blood lymphocyte population following 131I treatment for nodular goiter.

The blood lymphocyte population was examined in 34 patients who were treated with 131I for toxic or atoxic nodular goiter. The patients received one to three doses of 300-550 MBq of 131I administered at 1 week intervals. Lymphocyte counts were significantly reduced both 1 and 6 weeks after treatment. This reduction was accompanied by a changed composition of the lymphocyte population. The frequency of lymphocytes expressing membrane receptors for C'3 (EAC-rosette forming) was significantly reduced 1 and 6 weeks after 131I-administration. At 6 weeks there was a slight but statistically significant increase of the frequency of T-cells as identified by Leu 1 monoclonal antibodies. This was largely caused by an increased proportion of helper/induced T-cells as identified by Leu 3a monoclonals. 131I-treatment also reduced the capacity of lymphocytes to secrete immunoglobulins (Ig) upon PWM-stimulation. The most pronounced effect was observed for IgM. Secretion of IgG and IgA were less reduced. Mitogenic stimulations of lymphocytes with PHA and ConA were not significantly changed. We conclude that these changes observed, with the exception of mitogen reactivity, are essentially similar to those occurring after external radiation therapy for cancer. We speculate that blood lymphocytes passing through the continuously irradiated gland are damaged mainly by emitted beta-particles.

Long term effects on the immune system following local radiation therapy for breast cancer. I. Cellular composition of the peripheral blood lymphocyte population.

Local radiation therapy for breast cancer depletes the blood of various subsets of lymphocytes. Previous studies showed that the recovery is still incomplete at 30 months. To further elucidate the recovery we examined blood lymphocyte counts of 138 disease-free women and various lymphocyte subsets in 102 of these patients. These patients, 5-6 and 10-11 years earlier, had entered a clinical trial in which preoperative irradiation (45 Gy) was evaluated against postoperative irradiation (45 Gy) or surgery only. Patients who had undergone surgery only served as controls. Total lymphocyte counts of the irradiated patients were still significantly reduced 10-11 years after treatment. This reduction was mainly attributable to a subnormal level of T-cells as determined by the monoclonal antibody Leu-1 and the ability to form rosettes with sheep erythrocytes, whereas the number of non-T cells, expressing C'3 receptors, did not differ significantly from the controls. Within the T-cell population a subset with helper/inducer phenotypes, detected by Leu-3a antibodies, was significantly reduced even 10-11 years after irradiation. T-cells with suppressor/cytotoxic phenotypes, stainable with Leu-2a antibodies, however, had already recovered 5-6 years after irradiation. The duration of the radiation induced reductions of different lymphocyte subsets may be related to the physiological turn-over of the cells or a changed distribution of cells in the body.

Bestatin treatment of human lymphocytes increases the frequency of sheep red blood cell-binding cells.

Treatment of cancer patients with Bestatin, a new immunomodulator increases the frequency of peripheral lymphocytes forming rosettes with sheep red blood cells (SRBC). This study has shown that treatment of lymphocytes from healthy donors with Bestatin in vitro increases the frequency of such cells and there is a slight decrease of C'3-receptor bearing cells. The proportions of TM and TG cells were not significantly changed. The results indicate that the increased frequency of SRBC-binding cells during Bestatin medication is not due to a mobilisation of T-cells but rather to an improved binding capacity of certain T-cells for SRBC.