Palbociclib combined with endocrine treatment in hormone receptor-positive, HER2-negative breast cancer patients with high relapse risk after neoadjuvant chemotherapy: subgroup analyses of premenopausal patients in PENELOPE-B.

BACKGROUND: The PENELOPE-B study demonstrated that the addition of 1-year post-neoadjuvant palbociclib to endocrine therapy (ET) in patients with high-risk early breast cancer (BC) did not improve invasive disease-free survival (iDFS) compared to placebo. Here, we report results for premenopausal women. PATIENTS AND METHODS: Patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative BC at high risk of relapse [defined as no pathological complete response after neoadjuvant chemotherapy and a clinical, pathological stage, estrogen receptor, grading (CPS-EG) score ≥3 or 2/ypN+] were randomized to receive 13 cycles of palbociclib or placebo + standard ET. Ovarian function (OF) was evaluated by centrally assessed estradiol, follicle-stimulating hormone and anti-Müllerian hormone serum levels. RESULTS: Overall, 616 of 1250 randomized patients were premenopausal; of these, 30.0% were <40 years of age, 47.4% had four or more metastatic lymph nodes, and 58.2% had a CPS-EG score ≥3. 66.1% of patients were treated with tamoxifen alone, and 32.9% received ovarian function suppression (OFS) in addition to either tamoxifen or aromatase inhibitor (AI). After a median follow-up of 42.8 months (97.2% completeness) no difference in iDFS between palbociclib and placebo was observed [hazard ratio = 0.95, 95% confidence interval (CI) 0.69-1.30, P = 0.737]. The estimated 3-year iDFS rate was marginally higher in the palbociclib arm (80.6% versus 78.3%). Three year iDFS was higher in patients receiving AI than tamoxifen plus OFS or tamoxifen alone (86.0% versus 78.6% versus 78.0%). Patients receiving tamoxifen plus OFS showed a favorable iDFS with palbociclib (83.0% versus 74.1%, hazard ratio = 0.52, 95% CI 0.27-1.02, P = 0.057). Hematologic adverse events were more frequent with palbociclib (76.1% versus 1.9% grade 3-4, P < 0.001). Palbociclib seems not to negatively impact the OF throughout the treatment period. CONCLUSIONS: In premenopausal women, who received tamoxifen plus OFS as ET, the addition of palbociclib to ET results in a favorable iDFS. The safety profile seems favorable and in contrast to chemotherapy palbociclib does not impact OF throughout the treatment period.

Effect of preoperative chemotherapy on the outcome of women with operable breast cancer.

PURPOSE: To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies. PATIENTS AND METHODS: Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response. RESULTS: There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model. CONCLUSION: Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Recommendations from an international expert panel on the use of neoadjuvant (primary) systemic treatment of operable breast cancer: new perspectives 2006.

Neoadjuvant (primary systemic) treatment has become a standard option for primary operable disease for patients who are candidates for adjuvant systemic chemotherapy, irrespective of the size of the tumor. Because of new treatments and new understandings of breast cancer, however, recommendations published in 2006 regarding neoadjuvant treatment for operable disease required updating. Therefore, a third international panel of representatives of a number of breast cancer clinical research groups was convened in September 2006 to update these recommendations. As part of this effort, data published to date were critically reviewed and indications for neoadjuvant treatment were newly defined.

Tumor-specific suppressor T-cells which inhibit the in vitro generation of cytolytic T-cells from immune and early tumor-bearing host spleens.

Spleen cells from DBA/2 mice, after immunization with syngeneic P815 mastocytoma cells and Corynebacterium parvum, respond to P815 in vitro with a brisk, secondary-type generation of cytotoxic cells. This cytotoxicity is mediated by antigen-specific T-lymphocytes and correlates with resistance to in vivo challenge. This model confirms the observations of previous investigators made in semisyngeneic hosts using an in vivo transfer model. Spleen cells from "early" tumor-bearing hosts (TBHs), 7-12 days after intradermal (i.d.) inoculation of 10(6) P815 cells alone, made a similar, but generally higher, cytotoxic T-lymphocyte (CTL) response in vitro. Spleen cells from "late" TBHs (18-28 days) completely suppressed the in vitro CTL response of immune cells (e.g., from 71% specific release in controls down to 8% at an effector: target ratio of 40:1). Early i.d. TBH spleen cells, because of their higher level response, appeared to be resistant to this suppression (85% release for controls and 84% when suppressor cells were added at 40:1). By testing early TBH CTL at lower effector: target ratios, however, suppression by late TBH spleen cells could be readily demonstrated. When TBHs were inoculated s.c. instead of i.d. or with lower doses of tumor cells, responses were lower and susceptibility of splenic CTLs to suppression was increased. At intermediate times after tumor inoculation (14-20 days), spleen cells from TBHs still can respond in vitro, but they are completely suppressed by spleen cells from late TBHs. The suppressor cells are antigen-specific, radiation-sensitive, Thy1+ cells.

Phenotype of syngeneic tumor-specific cytotoxic T-lymphocytes and requirements for their in vitro generation from tumor-bearing host and immune spleens.

Cells required for the in vitro generation of syngeneic cytotoxic T-lymphocytes (CTL) against the P815 mastocytoma in the DBA/2 mouse strain were investigated. For both immune and tumor-bearing host spleen cells, CTL effector cells were eliminated by treatment with anti-Thy1.2, anti-Lyt1.1, or anti-Lyt2.1 and C', but were resistant to anti-L3T4 (GK1.5). Thus, CTL effectors (and their precursors) were Lyt1+2+, L3T4-. However, P815-specific CTL could not be generated in the absence of L3T4+ cells, whose function could be replaced with exogenous interleukin-2 (IL-2). When monoclonal antibodies against L3T4 were added to mixed leukocyte tumor cultures, CTL generation was markedly inhibited. Depletion of accessory cells also led to a marked reduction in CTL generation, which could be restored to control levels by adding adherent cells from normal spleens or with exogenous IL-2, but not with IL-1. Thus, accessory cells are apparently required to present the tumor antigens of this Ia-negative tumor to T-helper cells.

gamma-Interferon plays a key role in T-cell-induced tumor regression.

Recent studies have demonstrated that noncytolytic T-cells can mediate regression of murine tumors. In this report, we demonstrate that MCA-105 tumor-draining lymph node cells (DLN) activated with the protein kinase C activator, bryostatin 1, plus a calcium ionophore are capable of inducing specific tumor regression in vivo when adoptively transferred to mice with established metastases. However, these activated DLN cells lack in vitro cytotoxicity against autologous tumor. Antibody against gamma-interferon (IFN-gamma) markedly inhibited the therapeutic efficacy of these activated DLN cells. Anti-tumor necrosis factor produced a statistically significant but weaker inhibition of tumor regression. IFN-gamma, but not tumor necrosis factor alpha, could be shown to be secreted by activated DLN cells in vitro in response to specific tumor. Secretion of IFN-gamma was primarily a function of CD8+ T-cells. IFN-gamma was not directly cytotoxic to sarcoma cells in vitro. Moreover, tumor cells incubated with IFN-gamma were not more susceptible to lysis by activated DLN cells. However, recombinant murine IFN-gamma had a significant antiproliferative effect against MCA-105 tumor cells when tested in a [3H]thymidine uptake assay. Similarly, supernatants obtained from DLN/autologous tumor cocultures markedly inhibited MCA-105 proliferation; this antiproliferative effect was abrogated by the addition of anti-IFN-gamma antibody to the cultures. These results suggest that secretion of IFN-gamma by adoptively transferred DLN cells plays an essential role in tumor rejection. The dominant effect of IFN-gamma may be its demonstrated antiproliferative activity.

Inhibition of tumor-specific cytotoxic T-lymphocyte responses by transforming growth factor beta 1.

Transforming growth factor beta (TGF-beta) is a potent immunosuppressive cytokine that is produced by neoplastic and normal cells. It has not been demonstrated directly, however, that TGF-beta can inhibit antigen-specific T-cell responses to tumor cells in vitro. We show here that generation of antitumor cytotoxic T-lymphocyte (CTL) activity in mixed-lymphocyte tumor cultures of splenocytes from DBA/2 mice immunized with the syngeneic P815 mastocytoma + Corynebacterium parvum was consistently and profoundly inhibited when 0.675 to 10 ng/ml of TGF-beta were added on Day 0 of culture. TGF-beta added on Day 1 or later had little or no effect. In contrast to the results with P815 immune mice, mixed-lymphocyte tumor cultures established with splenocytes from P815 tumor-bearing hosts showed variable degrees of inhibition by TGF-beta, depending on the stage of the ongoing in vivo immune response. Addition of recombinant murine tumor necrosis factor alpha (1,000 or 10,000 units/ml) partially reversed inhibition of CTL responses by TGF-beta, while recombinant interleukin 2 nearly completely reversed the suppression. These data indicate that one level at which TGF-beta may act to inhibit mixed-lymphocyte tumor cultures is that of cytokine production. To determine whether TGF-beta also has any direct effect on CTL, P815-specific CTL clones derived from tumor-bearing host mice were utilized. We found that proliferation of rested CTL clones in response to tumor cells + interleukin 2 was inhibited by 5 ng/ml of TGF-beta, while the interleukin 2-dependent reactivation of cytolytic activity was not affected by TGF-beta. In contrast to rested CTL, when TGF-beta was added to cultures of previously activated CTL, proliferation was not inhibited. These data demonstrate that TGF-beta has profound inhibitory effects on the in vitro generation of effector CTL from tumor-specific murine splenocytes, and this inhibition may be an indirect result of suppressed cytokine production as well as a direct antiproliferative effect on CTL.

Activation and growth of murine tumor-specific T-cells which have in vivo activity with bryostatin 1.

We examined the ability of bryostatin 1 (Bryo), a novel protein kinase C activator, plus ionomycin (Io), a calcium ionophore, to activate T-cells with specific antitumor activity. Lymphocytes from the draining lymph nodes (DLN) of MCA-105 tumor-bearing host mice were stimulated with Bryo/Io, either fresh or after in vitro stimulation with autologous tumor, and then were incubated in interleukin-2 at 20 units/ml. Lymphocytes sensitized with tumor cells in vitro and then stimulated with Bryo/Io exhibited significant expansion (12-fold) after a total of 3 weeks in culture and moderate cytolytic activity (40% at an effector:tumor cell ratio of (80:1) and were exclusively CD8+ T-cells. DLN cells activated immediately with Bryo/Io, without tumor antigen sensitization in vitro, displayed marked growth (130-fold expansion) over 3 weeks in culture, had weak cytolytic activity (8% at an effector:tumor ratio of 80:1), and were a mixed population of CD8+ and CD4+ cells. Despite the differences in phenotypes and in cytotoxicity, both groups of DLN cells were highly effective in vivo against MCA-105 pulmonary metastases. Bryo/Io-activated DLN cells from MCA-105 tumor-bearing hosts had no therapeutic efficacy against B16 melanoma or MCA-203 sarcoma metastases. Lymph node cells from normal mice and non-draining lymph node cells from tumor-bearing hosts could be expanded with Bryo/Io to a degree similar to that of DLN cells but had no antitumor activity. Phenotypic analyses and in vitro and in vivo depletion studies demonstrate that CD8+ cells mediated tumor regression.

Trade-offs between survival and breast preservation for three initial treatments of ductal carcinoma-in-situ of the breast.

PURPOSE: To assess the trade-offs between survival and breast preservation of currently accepted approaches for ductal carcinoma-in-situ (DCIS) of the breast. PATIENTS AND METHODS: Decision analysis was performed using the Markov model of hypothetical cohorts of 55-year-old white women with nonpalpable mammographic abnormalities found to be DCIS. Strategies were breast-conserving surgery (BCS), BCS with 50-Gy radiation (RT) or initial mastectomy. Recurrence rates were derived from the published literature. Main outcomes were overall, breast cancer-free, and event-free survival plus years of both breasts preserved. RESULTS: Using the conditions defined in this model, the actuarial survival rates at 10 and 20 years were 91.7% and 74.1% for the initial mastectomy strategy, 91.0% and 72.1% for BCS plus RT, and 89.6% and 68.2% for BCS alone. At 20 years, the initial mastectomy strategy also had a greater breast cancer-free survival rate of 74.5%, compared with 63.3% for BCS plus RT, or 46.8% for BCS alone. However, BCS alone had the highest survival rate with both breasts preserved (64.2%) compared with BCS plus RT (56.0%) or initial mastectomy (0%). Of the breast-conserving strategies at 20 years, the breast event-free survival rate (no invasive cancer or DCIS) was greater for BCS plus RT (47.2%) compared with BCS alone (28.4%). Using just survival as the primary end point, mastectomy is the optimal strategy by a small margin. However, if quality-adjusted survival is at issue, mastectomy is the choice only if the yearly reduction in quality of life due to mastectomy is less than 1%. CONCLUSION: BCS with or without radiation compared with mastectomy as initial management of DCIS of the breast trades a slight decrease in survival rates for the value of breast preservation. This model should aid clinicians in matching treatments to their patients' preferences.

Comparative efficacy of adjuvant chemotherapy in patients with Dukes' B versus Dukes' C colon cancer: results from four National Surgical Adjuvant Breast and Bowel Project adjuvant studies (C-01, C-02, C-03, and C-04)

PURPOSE: Although the benefit from adjuvant chemotherapy has been clearly established in patients with Dukes' C colon cancer, such benefit has been questioned in patients with Dukes' B disease. To determine whether patients with Dukes' B disease benefit from adjuvant chemotherapy and to evaluate the magnitude of the benefit, compared with that observed in Dukes' C patients, we examined the relative efficacy of adjuvant chemotherapy according to Dukes' stage in four sequential National Surgical Adjuvant Breast and Bowel Project trials (C-01, C-02, C-03, and C-04) that compared different adjuvant chemotherapy regimens with each other or with no adjuvant treatment. PATIENTS AND METHODS: The four trials included Dukes' B and C patients and were conducted between 1977 and 1990. The eligibility criteria and follow-up requirements were similar for all four trials. Protocol C-01 compared adjuvant semustine, vincristine, and fluorouracil (5-FU) (MOF regimen) with operation alone. Protocol C-02 compared the perioperative administration of a portal venous infusion of 5-FU with operation alone. Protocol C-03 compared adjuvant 5-FU and leucovorin (LV) with adjuvant MOF. Protocol C-04 compared adjuvant 5-FU and LV with 5-FU and levamisole (LEV) and with the combination of 5-FU, LV, and LEV. RESULTS: Forty-one percent of the patients included in these four trials had resected Dukes' B tumors. In all four studies, the overall, disease-free, and recurrence-free survival improvement noted for all patients was evident in both Dukes' B and Dukes' C patients. When the relative efficacy of chemotherapy was examined, there was always an observed reduction in mortality, recurrence, or disease-free survival event, irrespective of Dukes' stage, and in most instances, the reduction was as great or greater for Dukes' B patients as for Dukes' C patients. When data from all four trials were examined in a combined analysis, the mortality reduction was 30% for Dukes' B patients versus 18% for Dukes' C patients. The mortality reduction in Dukes' B patients occurred irrespective of the presence or absence of adverse prognostic factors. CONCLUSION: Patients with Dukes' B colon cancer benefit from adjuvant chemotherapy and should be presented with this treatment option. Regardless of the presence or absence of other clinical prognostic factors, Dukes' B patients seem to benefit from chemotherapy administration.

Clinical trial to assess the relative efficacy of fluorouracil and leucovorin, fluorouracil and levamisole, and fluorouracil, leucovorin, and levamisole in patients with Dukes' B and C carcinoma of the colon: results from National Surgical Adjuvant Breast and Bowel Project C-04.

PURPOSE: To compare the efficacy of leucovorin-modulated fluorouracil (FU+LV) with that of fluorouracil and levamisole (FU+LEV) or with the combination of FU+LV and levamisole (FU+LV+LEV). PATIENTS AND METHODS: Between July 1989 and December 1990, 2,151 patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the colon were entered onto National Surgical Adjuvant Breast and Bowl Project protocol C-04. Patients were randomly assigned to receive FU+LV (weekly regimen), FU + LEV, or the combination of FU+LV+LEV. The average time on study was 86 months. RESULTS: A pairwise comparison between patients treated with FU+LV or FU+LEV disclosed a prolongation in disease-free survival (DFS) in favor of the FU+LV group (65% v 60%; P =.04); there was a small prolongation in overall survival that was of borderline significance (74% v 70%; P =.07). There was no difference in the pairwise comparison between patients who received FU+LV or FU+LV+LEV for either DFS (65% v 64%; P =.67) or overall survival (74% v 73%; P =.99). There was no interaction between Dukes' stage and the effect of treatment. CONCLUSION: In patients with Dukes' B and C carcinoma of the colon, treatment with FU+LV seems to confer a small DFS advantage and a borderline prolongation in overall survival when compared with treatment with FU+LEV. The addition of LEV to FU+LV does not provide any additional benefit over and above that achieved with FU+LV. These findings support the use of adjuvant FU+LV as an acceptable therapeutic standard in patients with Dukes' B and C carcinoma of the colon.

Effect of preoperative chemotherapy on the outcome of women with operable breast cancer.

PURPOSE: To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies. PATIENTS AND METHODS: Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response. RESULTS: There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model. CONCLUSION: Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Effect of AS101 on bryostatin 1-mediated differentiation induction, cell cycle arrest, and modulation of drug-induced apoptosis in human myeloid leukemia cells.

Based upon earlier reports of synergism in cells of lymphoid origin, we have examined interactions between the organotellurium compound AS101 and the protein kinase C (PKC) activator bryostatin 1 with respect to differentiation and Ara-C-induced apoptosis in human myeloid leukemia cells (HL-60). Although preincubation with bryostatin 1 (10 nM) for 24 h significantly increased DNA fragmentation and apoptosis in cells subsequently treated with 10 microM Ara-C for 6 h, this effect was not enhanced by co-administration of AS101 (1.5 microM). However, while exposure of cells to AS101 or bryostatin 1 alone for 72 h was ineffective in inducing cellular maturation, combined treatment resulted in the induction of differentiated features in a subset of cells, manifested by an increase in cell adherence, CD11b expression, cytoplasmic granularity and cell spreading. In addition, cells exposed to the combination of AS101 and bryostatin 1, in contrast to cells incubated with these agents individually, displayed a significant decline in the S-phase and a corresponding increase in the G0/G1 cell populations. These events were accompanied by an increase in protein expression of the cyclin-dependent kinase inhibitor, p21 (WAF1/CIP1/MDA6), and a decline in expression of the c-myc protein. AS101 failed to increase intracellular free Ca2+ ([Ca2+]i) in HL-60 cells, or reverse the profound PKC down-regulation induced by bryostatin 1. Whereas treatment of cells with 1.5 microM AS101 or 10 nM bryostatin 1 for 24 h exerted minimal growth inhibitory effects, combined exposure to these agents reduced colony formation by over 70%. Finally, although addition of AS101 did not potentiate apoptosis induced by the bryostatin 1/Ara-C combination, it did lead to a further reduction in clonogenicity. Together, these findings demonstrate that AS101 partially restores the ability of bryostatin 1 to trigger a differentiation program in an otherwise unresponsive HL-60 cell line, possibly by facilitating bryostatin 1-mediated G1 arrest. They also indicate that AS101 potentiates the antiproliferative effects of bryostatin 1 administered alone or in combination with Ara-C through a mechanism other than, or in addition to, induction of apoptosis.

Phase Ib trial of bryostatin 1 in patients with refractory malignancies.

A Phase Ib trial of bryostatin 1, a macrocyclic lactone and protein kinase C (PKC) activator, was conducted in patients with refractory nonhematological malignancies with the primary goal of determining whether down-regulation of peripheral blood mononuclear cell (PBMNC) PKC activity could be achieved in vivo in humans. Patients (four patients/cohort) received bryostatin 1 (25 microg/m2) as a 1-h infusion weekly three times every 4 weeks, but to study the schedule dependence of pharmacokinetics and pharmacodynamics, the first dose was administered according to one of three schedules: (a) a 1-h infusion; (b) a 24-h infusion; or (c) a split course (12.5 microg/m2 as a 30-min infusion) on days 1 and 4. Conventional toxicities (grades I-III) included myalgias, fever, anemia, fatigue, phlebitis, and headache; in addition, two patients in cohort 3 experienced transient elevations in liver function tests, although these patients had preexisting liver metastases. No objective clinical responses were encountered. Effects on PBMNC PKC activity were heterogeneous. Several patients in cohorts 1 and 2 experienced significant declines in activity (approximately 50%) that were sustained in some cases for periods of > or = 72 h. Comparison of 72-h with baseline values for all three patient cohorts combined revealed a trend toward PKC down-regulation (P = 0.06; signed rank test). For each schedule, plasma bryostatin 1 levels were below the level of detection of a platelet aggregation-based bioassay (3-4 nm). Bryostatin 1 administration failed to produce consistent alterations in lymphocyte immunophenotypic profiles, interleukin 2-induced proliferation, or cytotoxicity, although two of three samples from patients in cohort 3 did show significant posttreatment increases in proliferation. Moreover, in some patients, bryostatin 1 treatment increased lymphokine-activated killer cell activity. These findings indicate that bryostatin 1 doses of 25 microg/m2 can induce in vivo PBMNC PKC down-regulation in at least a subset of patients and raise the possibility that higher bryostatin 1 doses may be more effective in achieving this effect.

Activation of CD8+ murine T cells from tumor-draining lymph nodes by phorbol dibutyrate plus calcium ionophore.

When lymphocytes from the lymph nodes draining the site of a progressively growing MCA-105 sarcoma are stimulated in vitro with autologous tumor and low-dose interleukin-2 (IL-2), they will grow and develop the ability to lyse autologous tumor cells in vitro; these lymphocytes can also eradicate tumor metastases in vivo. Phorbol esters and calcium ionophores activate signal transduction pathways in T cells and mimic the events triggered by antigen binding. We therefore sought to determine whether large numbers of MCA-105 tumor-specific, therapeutically active T cells could be obtained from MCA-105 draining lymph nodes (DLNs) following a brief exposure to phorbol dibutyrate (PDBu) and ionomycin (Io). DLN cells primarily stimulated with autologous tumor, followed by a secondary stimulation with PDBu-Io and cultured in 20 U/ml IL-2, demonstrated marked expansion of cell numbers during 3 weeks in culture, had moderate cytolytic activity [37% at effector:target ratio (E:T) = 80:1], and were all CD8+ T cells. In contrast, DLN cells stimulated primarily with PDBu-Io and cultured in 20 U/ml IL-2 demonstrated at least 8-10-fold greater growth than antigen-stimulated DLN cells during 3 weeks, were moderately cytolytic (31% at E:T = 80:1), and were a mixed population of CD8+ and CD4+ T lymphocytes. DLN cells that were expanded by either protocol, like cells stimulated repeatedly in vitro with tumor cells, could eliminate MCA-105 pulmonary metastases when given with IL-2 in an adoptive immunotherapy model. DLN cells stimulated primarily with PDBu-Io completely eradicated MCA-105 metastases but had no in vivo antitumor activity against the syngeneic B16 melanoma or MCA-203 sarcoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Bryostatin 1 activates T cells that have antitumor activity.

Several strategies have been used to stimulate the growth of tumor-specific T cells in place of tumor antigen. One approach is to use pharmacologic agents to activate the second messenger pathways of T-cell activation. In the present study, we examined the ability of the protein kinase C activator bryostatin 1 (B) plus the calcium ionophore ionomycin (I) to stimulate the growth of lymphocytes obtained from the axillary lymph nodes (DLN) draining a progressively growing intradermal plasmacytoma tumor. Draining lymph node cells were initially cultured with autologous tumor cells and 20 U/ml of interleukin-2 (IL-2) for 7 days. The lymphocytes were then incubated with various concentrations of bryostatin 1 plus 1 microM ionomycin and cultured for an additional 14 days in IL-2. DLN cells initially cultured with autologous tumor and then restimulated with 5 nM bryostatin 1 and 1 microM ionomycin exhibited marked in vitro proliferation and 15-fold expansion of cell numbers over 2 weeks. The cells expanded with B/I were predominantly CD8+ T cells and retained specific in vitro cytotoxicity against autologous tumor. When adoptively transferred to mice with established liver metastases, DLN cells restimulated with B/I-mediated specific tumor regression.

Accelerated superfractionated radiotherapy for inflammatory breast carcinoma: complete response predicts outcome and allows for breast conservation.

PURPOSE: Chemotherapy and accelerated superfractionated radiotherapy were prospectively applied for inflammatory breast carcinoma with the intent of breast conservation. The efficacy, failure patterns, and patient tolerance utilizing this approach were analyzed. METHODS AND MATERIALS: Between 1983 and 1996, 52 patients with inflammatory breast carcinoma presented to the Medical College of Virginia Hospitals of VCU and the New England Medical Center. Thirty-eight of these patients were jointly evaluated in multidisciplinary breast clinics and managed according to a defined prospectively applied treatment policy. Patients received induction chemotherapy, accelerated superfractionated radiotherapy, selected use of mastectomy, and concluded with additional chemotherapy. The majority were treated with 1.5 Gy twice daily to field arrangements covering the entire breast and regional lymphatics. An additional 18-21 Gy was then delivered to the breast and clinically involved nodal regions. Total dose to clinically involved areas was 63-66 Gy. Following chemoradiotherapy, patients were evaluated with physical examination, mammogram, and fine needle aspiration x 3. Mastectomy was reserved for those patients with evidence of persistent or progressive disease in the involved breast. All patients received additional chemotherapy. RESULTS: Median age was 51 years. Median follow-up was 23.9 months (6-86) months. The breast preservation rate at the time of last follow-up was 74%. The treated breast or chest wall as the first site of failure occurred in only 13%, and the ultimate local control rate with the selected use of mastectomy was 74%. Ten patients underwent mastectomy, 2 of which had pathologically negative specimens despite a clinically palpable residual mass. Response to chemotherapy was predictive of treatment outcome. Of the 15 patients achieving a complete response, 87% remain locoregionally controlled without the use of mastectomy. Five-year overall survival for complete responders was 68%. This is in contrast to the 14% 5-year overall survival observed with incomplete responders. The 5-year actuarial disease-free survival and overall survival for the entire patient cohort was 11% and 33%, respectively. All patients tolerated irradiation with limited acute effects, of which all were managed conservatively. CONCLUSION: Our experience demonstrates that induction chemotherapy, accelerated superfractionated radiotherapy, and the selected use of mastectomy results in excellent locoregional control rates, is well tolerated, and optimizes breast preservation. Based on our present results, we recommend that a patient's response to induction chemotherapy guide the treatment approach used for locoregional disease, such that mastectomy be reserved for incomplete responders and avoided in those achieving a complete response.

Generation of cytotoxic T lymphocytes from peripheral blood.

BACKGROUND: Cytotoxic T lymphocytes (CTL) have been shown to be useful for adoptive immunotherapy in malignancy. Traditional sources for CTL, such as tumor-infiltrating lymphocytes, have limitations. It would therefore be useful to develop a method of generating antitumor CTL from a renewable source such as peripheral blood. METHODS: DBA/2 mice were injected intradermally in the abdominal wall with the murine tumor PHS-5 and killed 14 days later. Peripheral blood lymphocytes were harvested and cultured with 20 units/ml interleukin-2 and autologous tumor-stimulator cells treated with mitomycin C. Cultures were split when greater than 2 x 10(6) cells/well, fed every 3 days and stimulated weekly. RESULTS: Lymphocytes expanded greater than 130,000-fold during 8 weeks. Specific cytotoxicity was shown with 51Cr release assay. Withdrawal of repeated stimulation with autologous tumor resulted in failure of cells to expand in culture and loss of cytotoxicity. In vivo administration showed marked reduction of 10-day liver metastases, indicating therapeutic efficacy. CONCLUSIONS: These data demonstrate a successful animal model of adoptive immunotherapy with CTL generated from peripheral blood lymphocytes.

A cytotoxic T-lymphocyte clone derived from mice with progressively growing tumors.

Tumor-specific T-cell clones were derived from spleen cells of mice bearing a syngeneic PHS-5 tumor (a P815 mastocytoma mutant). Cells were expanded in vitro and characterized and assayed for activity against the relevant tumor in vivo. Clone cells were CD4-, CD8+ T lymphocytes, as determined by fluorescence activated cell sorting analysis and were specifically cytotoxic against P815 tumor cells in vitro, as shown in chromium 51 release assays. These cells require both antigen and interleukin 2 to proliferate; neither alone is sufficient, even with the addition of interleukin 1. In an experimental P815 liver metastasis model, the adoptive transfer of GD11 or GD11.17 clone cells and injection of recombinant interleukin 2 (7500 U intraperitoneally) 3 days after infusion of tumor cells reduced the number of tumor nodules, while the adoptive transfer of lymphokine-activated killer cells was ineffective.

Conditioning lesions of peripheral nerves change regenerated axon numbers.

The present study investigates the effects of conditioning lesions on regenerated axon numbers in tributary nerves after a test lesion. If a rat sciatic nerve is crushed 7 and 14 days prior to a test crush, the numbers of regenerated myelinated axons 8 weeks later in the sural nerve (SN) and nerve to the medial gastrocnemius (NMG) are increased, both over normal and over numbers after a single crush. If the lesions are only separated by 2 days, however, the numbers are similar to the numbers after a single crush. Thus conditioning occurs, but a minimum time between crushes is necessary for the effects of conditioning to be manifest. If the intervals between lesions are 14 days, the numbers are similar to those after the 7-day intervals. Moving each successive crush proximally or distally does not change regenerated myelinated axon numbers. Thus increasing the time between lesions after conditioning occurs, at least within the constraints of our paradigm, does not change regenerated axon numbers and the location of the lesion has relatively little bearing on the numbers of axons that regenerate. These findings allow us to change axonal numbers in these tributary nerves in a predictable way, and they are also compatible with the hypothesis that conditioning results from priming of the cell body rather than changes in the environment of the regenerating axons.