Modulation of deoxycytidine kinase (dCK) and glycogen synthase kinase (GSK-3ß) by anti-CD20 (rituximab) and 2-chlorodeoxyadenosine (2-CdA) in human lymphoid malignancies.

BACKGROUND: The combination of rituximab and 2-CdA is an effective therapy for B-cell tumors. However, the molecular mechanisms and enzymatic pathways involved in the interaction between the two agents are not fully understood. In this study, we provide molecular evidence for positive interaction between these two agents with resultant therapeutic benefit. METHODS: Efficacy of the R-2CdA regimen was evaluated in thirteen patients with B-cell tumors (9 CLL; 3 WM and 1 FL), in vitro against 3 lymphoma cell lines and in a xenograft mouse model. Treatment-induced changes involving phenotype, kinase activity and protein expression were assessed in vitro and in the mouse xenograft tumors. The interaction between RTX and 2-CdA was analyzed using the multiple comparison method, Tukey's honestly significant difference (HSD). For the clinical and animal data, survival functions were estimated using the Kaplan-Meier method and compared by the log-rank test. P-values <0.05 were considered statistically significant. All statistical analyses were evaluated using GraphPad Prism 4 (San Diego, CA). RESULTS: 9 of 12 (75%) evaluable patients responded to the R-2-CdA regimen with median duration of response of 34 months. Median survival of patients from diagnosis and from completion of R-2-CdA treatment was 13.3 and 7.9 years, respectively. In vitro, the combination was effective in all 3 cell lines of lymphomas but with higher sensitivity in the follicular lymphoma cell line. The combination was also effective in the WSU-WM-SCID xenograft model with dose-dependent response and synergistic benefit. All animals were tumor-free for up to 120 days post 2 cycles of this regimen. Rituximab induced activation of deoxycytidine kinase (dCK), p38 mitogen activated protein kinase (p38MAPK) and glycogen synthase kinase-3ß (GSK-3ß) in the xenograft WSU-WM tumors. Chemical inhibition of p38MAPK led to inhibition of the GSK-3ß phosphorylation suggesting that GSK-3ß is regulated by p38MAPK in this model. CONCLUSION: Collectively, our studies show concordance between the activity of R-2-CdA in vitro, in human and in WSU-WM xenograft model attesting to the validity of this model in predicting clinical response. Modulation of dCK and GSK-3ß by rituximab may contribute to the positive therapeutic interaction between rituximab and 2-CdA.

Salvage radiation for a rising PSA following radical prostatectomy.

The purpose of this study was to evaluate the efficacy and complications of postprostatectomy therapeutic irradiation (RT) in patients with known residual disease. Between 1991 and 2003, 170 patients received therapeutic irradiation for a rising PSA following radical prostatectomy. No patients had clinical or radiological evidence of metastatic disease. The median pre-RT PSA level was 1.2 ng/mL (range, 0.2-43 ng/mL). During irradiation, the PSA level was checked weekly (median PSA determinations: 5, range, 2-7). A patient was considered to have a rise/fall of PSA if the level changed by > or = 0.2 ng/mL. There were 149 patients who received photon irradiation (median dose, 6800 cGy) and 21 patients received a combination of photon and neutron irradiation to a median photon dose equivalent of 7800 cGy. A patient was considered to have biochemical failure if his PSA level postnadir was measured at >0.2 ng/mL. Complications were graded according to the RTOG toxicity scale. The median follow-up time was 49 months (range, 1-137 months). Sixty-four patients (38%) had evidence of biochemical failure. The 7 year overall survival was 84%. At 7 years, the actuarial biochemical relapse free survival (bRFS) was 44%. Of the 59 patients with a preradiation PSA <1 ng/mL, the 5 year bRFS was 81%. This compares with 45% for both the PSA 1-4 and PSA >4 ng/mL group (P = 0.00008). The 3-year bRFS rates for patients whose PSA levels increased, decreased, and remained the same during radiation were 20%, 65%, and 76%, respectively (P = 0.0005). Overall survival at 7 years in the decreased PSA group was 88% compared to 67% for those whose PSA level increased (P = 0.43). Thirty-three percent and 19% of the patients experienced Grade 2 genitourinary (GU) and gastrointestinal (GI) complications, respectively. Six percent and 3% of the patients had Grade 3 GU and GI complications, respectively. On univariate and multivariate analysis, the factors significantly associated with a favorable outcome were a declining PSA during RT and a pre-RT PSA <1 ng/mL (P < 0.001). Radiation therapy is an effective treatment modality for select patients with a biochemical recurrence following radical prostatectomy. Patients with a low preradiation PSA level (<1.0 ng/mL) had a significantly better outcome, which supports the early use of therapeutic radiation. The observation that patients with a rising PSA level during treatment do poorly supports the routine practice of monitoring these levels during radiotherapy.

Intermittent androgen deprivation for patients with recurrent/metastatic prostate cancer.

This study was designed to assess the duration of response to intermittent androgen deprivation therapy (IAD) in patients with recurrent and/or metastatic prostate cancer. Between January 1993 and March 2000, 74 patients with recurrent and/or metastatic prostate cancer had IAD with either luteinizing hormone-releasing hormone agonist (LHRH) or an LHRH with an oral antiandrogen. Forty-one patients were treated for an increasing prostate-specific antigen (PSA) level after primary local treatment. Of the remaining 33 patients, 17 patients were treated for metastases (9 for bone metastases, 8 for lymph nodes metastases, and 16 for local recurrence). Patients who had undergone IAD completed between 1 and 6 cycles. A cycle was defined as the period during which the patient was actively taking the hormone medication. Seventy-four patients completed the first cycle, 49 completed the second cycle, and 23 completed the third cycle. The pattern of PSA changes with each cycle, the length of each cycle, and the time interval between successive cycles were studied. The time to progression (defined as an increasing PSA level on two consecutive measurements or radiologic evidence of progression of disease while the patient was on androgen deprivation) was also studied. The median PSA before the IAD was 11.4 ng/mL (range 0.12-378). The median PSA nadir at the end of each cycle increased progressively (0.1 ng/mL after the first cycle to 3.3 ng/mL after the fifth cycle). The time interval between the cycles progressively decreased from 9.5 months between the first and second cycles to 6 months between the third and fourth cycles. The 4-year actuarial androgen-independent free survival was 71%. For the subgroups of patients treated for biochemical failure, locoregional recurrence, and bone metastases, the 4-year actuarial progression-free survival rates were 80%, 67%, and 45% respectively (P = 0.018). The median time of 18 months to progression in patients with bone metastases is similar to that reported with continuous hormonal therapy. In patients with biochemical failure, the median time to progression (more than 5 years) suggests that the IAD approach may be a viable option for this group of patients.

Radiation improves intratumoral gene therapy for induction of cancer vaccine in murine prostate carcinoma.

Our goal was to convert murine RM-9 prostate carcinoma cells in vivo into antigen-presenting cells capable of presenting endogenous tumor antigens and triggering a potent T-helper cell-mediated immune response essential for the generation of a specific antitumor response. We showed that generating the major histocompatibility complex (MHC) class I+/class II+/Ii- phenotype, within an established subcutaneous RM-9 tumor nodule, led to an effective immune response limiting tumor growth. This phenotype was created by intratumoral injection of plasmid cDNAs coding for interferon gamma, MHC class II transactivator, and an antisense reverse gene construct (RGC) for a segment of the gene for Ii protein (-92,97). While this protocol led to significant suppression of tumor growth, there were no disease-free survivors. Nevertheless, irradiation of the tumor nodule on the day preceding initiation of gene therapy yielded 7 of 16 mice that were disease-free in a long-term follow up of 57 days compared to 1 of 7 mice receiving radiotherapy alone. Mice receiving radiotherapy and gene therapy rejected challenge with parental RM-9 cells and demonstrated specific cytotoxic T-cell activity in their splenocytes but not the mouse cured by radiation alone. These data were reproduced in additional experiments and confirmed that tumor irradiation prior to gene therapy resulted in complete tumor regression and specific tumor immunity in more than 50% of the mice. Increasing the number of plasmid injections after tumor irradiation induced tumor regression in 70% of the mice. Administering radiation before this novel gene therapy approach, that creates an in situ tumor vaccine, holds promise for the treatment of human prostate carcinoma.

Permanent iodine-125 interstitial radiation therapy in the treatment of non-glioblastoma multiforme high-grade gliomas.

BACKGROUND: This study evaluates prognostic factors influencing survival outcomes for 60 patients with permanent iodine-125 implants in the primary treatment of non-glioblastoma multiforme (GBM) high-grade gliomas. METHODS: Stereotactic treatment planning aimed to encompass the contrast-enhancing rim of the tumor visualized by CT, with an initial dose rate of 0.05 Gy/h with 125I, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Survival was evaluated using the Kaplan-Meier method for univariate analysis and the Cox regressional method for multivariate analysis. In addition to the implant, 34 patients received external radiation therapy (5,000-6,000 cGy) before the implant; 13 patients were implanted without additional external beam radiation, and 13 patients underwent external radiation therapy before implant placement. RESULTS: With a mean follow-up of 77.6 months (range 3.5-164 months), 1-, 3-, 5- and 10-year survival were 86.7% (+/-0.05%), 60% (+/-0.07%), 50% (+/-0.07%) and 45.7% (+/-0.7%), respectively. The median survival time was 57 months. Second surgery was performed following the implant in 19 patients. Findings were tumor recurrence in 11 patients (22.5%), radiation necrosis in 7 patients (14.3%) and brain abscess in 1 patient (2%). Age, sex, tumor location, side of brain, tumor volume, Karnofsky score and neurological status were correlated with survival outcome. Favorable prognostic factors were age younger than 45 years, superficial tumor location and preoperative Karnofsky score greater than 70. RPA classification was used to define this group of patients. In RPA classes I and II (n = 43), 1-year survival was 93%, while 3-, 5- and 10-year survival was 67.4, 60.5 and 55.5%, respectively, and median survival time was 91 months. In RPA class III (n = 7), 1-year survival was 71.4%, while 3- and 5-year survival was 42.9 and 28.6%, respectively, and median survival time was 47 months. In RPA class IV (n = 10), 1-year survival was 60%, while 3-, 5- and 10-year survival was 50, 22.2 and 11.1%, respectively, and median survival time was 37 months. CONCLUSION: Brachytherapy with permanent implant of 125I appears promising in the treatment of primary non-GBM malignant gliomas. It improved survival time and reduced the incidence of complications and provided good quality of life. In order to further confirm these results, multicenter randomized prospective studies are needed. RPA analysis is a valid tool to define prognostically distinct survival groups. In this study, 2-year survival and median survival time were improved in all prognostic classes. This would suggest that selection bias alone does not account for the survival benefit seen with 125I implants. Further randomized studies with effective stratification are needed.

Lobular carcinoma in situ and invasive cancer: the contralateral breast controversy.

We determined if the risk of relapse is increased in patients with the concomitant diagnosis of lobular carcinoma in situ (LCIS) and an invasive cancer, suggesting the need for a more aggressive surgical approach. A retrospective chart review was conducted from the University of Michigan's Cancer Registry of patients with LCIS and a simultaneous invasive cancer and patients with invasive cancer only diagnosed between 1981 and 1997. The two groups were compared statistically with the following variables: age at diagnosis, tumor stage, histopathologic type of cancer, type of surgery, first line of treatment, relapse status with dates, site of relapse, and vital status. Statistically significant differences were found in the distribution of age (mean p = 0.0484 and median p = 0.0216), and histopathologic type of cancer (p < 0.0001). No significant difference was noted in the overall survival between the two groups (p = 0.511). There was also a significant difference in the relapse-free survival curves between the groups (p = 0.032). The risk of relapse was almost double (1.92) for the cancer-only patients relative to patients with LCIS as a histologic component of cancer. There was no significant increase in contralateral or ipsilateral breast recurrence for patients with LCIS and an invasive cancer compared to an invasive cancer alone. This lends support to the use of breast conservation therapy for invasive cancer patients with a histologic component of LCIS. The significant difference in the types of cancer may support the theory of genetic progression of LCIS to cancer, but clearly further data are required to prove this hypothesis.

Therapeutic postprostatectomy irradiation.

The purpose of this study was to determine the outcome of patients receiving external beam radiation for an elevated postprostatectomy prostate-specific antigen (PSA) level. Between December 1991 and September 1998, 108 patients received definitive radiation therapy for elevated postprostatectomy PSA levels. The median dose of irradiation was 68 Gy (range, 48-74 Gy). During treatment, the PSA levels were checked an average of 5 times (range, 3-7 times). Prostate-specific antigen values were judged to decline or increase during treatment if they changed by more than 0.2 ng/mL. After treatment, biochemical failure was defined as a measurable or rising PSA > 0.2 ng/mL. Median follow-up was 51 months (range, 3-112 months). Fifty-eight patients (54%) had evidence of biochemical failure. The 3- and 5-year actuarial biochemical relapse-free (bNED) survivals for all patients were 55% and 39%, respectively. Upon univariate analysis, intratreatment PSA and preradiation PSA were significant predictors of bNED survival. Patients with a PSA level that decreased during treatment had a 5-year bNED survival of 43% compared to 10% in patients with an increasing PSA level (P = 0.0002). Using the preradiation therapy PSA value as a continuous variable, higher preradiation therapy PSA levels were associated with an increased risk of failure (P = 0.004). Cut points of pretreatment PSA were derived at 0.9 ng/mL and 4.2 ng/mL using the Michael Leblanc recursive partitioning algorithm. The 5-year bNED rate for patients with a preradiation therapy PSA < 0.9 ng/mL was 45% versus 42% for patients with preradiation therapy PSA between 0.9 and 4.2 ng/mL and 21% for patients > or = 4.2 ng/mL (P = 0.0003). Patients with a Gleason score of < or = 7 had a 5-year bNED rate of 38% compared to 37% for patients with a Gleason score > 7 (P = 0.27). Other factors examined individually that did not reach statistical significance included time from surgery to radiation therapy, race, seminal vesicle involvement, pathological stage, surgical margin, and perineural invasion. Upon multivariate analysis, only preradiation therapy PSA (P < 0.001) and the PSA trend during radiation therapy (P < 0.001) were significant factors. The results of therapeutic radiation for patients with elevated postprostatectomy PSA levels are sufficiently poor; other strategies should be explored as alternatives, including early adjuvant postprostatectomy irradiation or the use of combined hormonal and radiation therapy in the salvage situation.