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Peter McLaughlin

Publications and source records attributed to Peter McLaughlin.

42 records · Page 3Linked to original sources

Progress and promise in the treatment of indolent lymphomas.

In the era of conventional alkylating agent-based chemotherapy, advanced stage indolent lymphoma has been considered incurable. The failure of our traditional therapies to cure these patients, coupled with the indolent course of the disease and the elderly population affected, has fostered a nihilistic attitude about the treatment of these diseases. Twenty years ago, in the absence of interesting alternatives to alkylating agents, judicious use and reuse of alkylators was perhaps the best we could do. There are now many reasons for optimism and excitement in the treatment of these diseases, including the availability of promising agents such as interferon-alpha, the nucleoside analogues, and rituximab. Radioimmunotherapy will also likely play a role in future therapy programs. Allogeneic stem cell transplantation is a high-risk approach that is not an option for all patients, but it has the potential to cure patients, even in the setting of relapse. Mini-allogeneic transplantation may permit an approach to allogeneic transplantation that is better tolerated than standard transplant strategies. In addition to these therapy options, biological insights have provided new options for monitoring patients. Molecular monitoring (polymerase chain reaction for bcl-2) is a stringent measure of short-term treatment efficacy, and one that correlates with durability of remission, i.e., it is a surrogate marker by which to judge treatment efficacy. There used to be a limited number of conventional treatment approaches, which consistently failed. The pendulum has swung. There are now many promising new options. It is time to plan and conduct trials that are geared for success.

Biomarkers, Tumor↗

Quantitative real-time polymerase chain reaction for monitoring minimal residual disease in patients with advanced indolent lymphomas treated with rituximab, fludarabine, mitoxantrone, and dexamethasone.

Fludarabine and rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA) are active against indolent lymphomas. We have previously shown the safety and efficacy of the combination of FND (fludarabine/mitoxantrone/dexamethasone) in relapsed and subsequently untreated patients with stage IV indolent lymphomas. Currently, we treat patients with stage IV indolent lymphomas who are previously untreated, younger than 60 years, human immunodeficiency virus-negative, and have adequate organ and marrow function with FND and random assignment to concurrent or delayed administration of rituximab. We have developed a quantitative real-time polymerase chain reaction assay for t(14;18). With 1 microg of DNA, this assay detects 0.6 copies in 55% of reactions, as expected for the Poisson distribution. When 1microg of DNA was analyzed in duplicate, cells with the t(14;18) were detected in peripheral blood of 22% of 152 volunteer blood donors. Quantitation showed that numbers of t(14;18) cells were higher than the statistical upper normal limit (mean of all volunteer values plus standard deviations) in 2% of volunteer blood donors. By contrast, 36% of blood or marrow specimens from follicular lymphoma patients were positive, and the number of cells with t(14;18) was higher than the normal upper limit in 26%. The presence of cells with t(14;18) and their numbers are prospectively quantitated in blood and marrow of patients treated with FND plus rituximab to determine their clinical significance both at presentation and during therapy.

Actins↗

Importance of esophagogastroduodenoscopy in the evaluation of non-gastrointestinal mucosa-associated lymphoid tissue lymphoma.

PURPOSE: Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B-cell lymphoma that most commonly presents in the gastrointestinal (GI) tract. However, it can present in non-GI primary sites. This study was conducted to determine the incidence of gastric involvement in non-GI presentation of MALT lymphoma. PATIENTS AND METHODS: We retrospectively reviewed the medical records of 36 consecutive patients who presented with non-GI MALT lymphoma and had EGD as a part of the initial staging work-up between 1992 and 2001. RESULTS: The median age was 62 years (range, 27-82); 27 were female patients. The frequency of the primary site was; salivary gland/parotid gland (N = 14), ocular adnexa (N = 7), lung (N = 3), oral cavity (N = 3), skin (N = 3), thyroid (N = 2), nasopharynx (N = 2), larynx (N = 1), breast (N = 1). Twelve patients were found to have gastric involvement; 2 additional patients progressed in the stomach 5 and 6 months later, respectively. DISCUSSION: Routine evaluation of the stomach should be a part of the initial staging work-up of non-GI MALT lymphoma.

Adult↗

Molecular response of follicular lymphoma to cyclophosphamide, doxorubicin, vincristine, prednisone C(H)OP or COP-based therapy as measured by polymerase chain reaction evidence of translocation (14;18)(q32;q21).

PURPOSE: Existing data suggest that conventional C(H)OP (cyclophosphamide, doxorubicin, vincristine, prednisone) regimen may not be intensive enough to achieve molecular response, as measured by polymerase chain reaction (PCR) evidence of translocation (14;18)(q32:q21) for follicular lymphoma. This study was undertaken to study the molecular response rate of follicular lymphoma to C(H)OP-based therapy and to analyze prognostic factors for molecular response. PATIENTS AND METHODS: Twenty patients with pretreatment PCR evidence of t(14;18)(q32; q21) and at least one posttreatment PCR analysis after the initiation of the treatment with C(H)OP with or without radiation therapy constituted the basis for this analysis. The random effects logistic model was used to analyze the data. The following factors were investigated for their relationship to molecular response: gender, age, beta2-microglobulin, use of radiation therapy, Ann Arbor stage, and international Prognostic Index for malignant lymphoma. RESULTS: Median follow-up was 56 months (range, 23-153 months). A total of 135 PCR results were available, 33 from bone marrow and 102 from peripheral blood. Overall, there was a clear and steady decreasing trend toward loss of PCR positivity with increasing time aftertreatment. By univariate analysis, stage > or = 3, stage = 4, International Prognostic Index > or = 2, and no radiation therapy were adverse factors for molecular response. On multivariate analysis, Ann Arbor stage IV and no radiation therapy were independent risk factors for PCR positivity, both for the peripheral blood data analyzed alone and for all data combined. DISCUSSION: It is possible to achieve molecular response with C(H)OP with or without radiation therapy in patients with follicular lymphoma. Response rate depends on the Ann Arbor stage and radiation therapy.

Adult↗

Pentostatin in T-non-Hodgkin's lymphomas: efficacy and effect on CD26+ T lymphocytes.

Pentostatin is an adenosine deaminase (ADA) inhibitor with antineoplastic activity. CD26 is a surface glycoprotein with a key role in T cell function as the ADA binding protein. We conducted a phase II study to evaluate pentostatin efficacy in relapsed T-non-Hodgkin's lymphoma (T-NHL) and to correlate response with tumor CD26 expression. We also examined the lymphopenic effect of pentostatin on CD26+ T lymphocytes. Eighteen patients were registered for the study. Pentostatin was administered as intravenous bolus daily over 3 days at an initial dose of 5 mg/m(2)/day, repeated every 4 weeks. CD26 surface expression on tumor cells and T lymphocytes was determined by flow cytometry. Out of 14 patients evaluable for response, there was 1 (7%) complete response (CR) and 6 (43%) partial responses (PR). Median progression-free survival for responders was 6 months (range: 2-15 months); median number of courses was 4 (range: 1-6). Responders included 1 of 2 CD26+ and 5 of 9 CD26- cases. Pentostatin also specifically depleted CD26+ rather than CD26- T lymphocytes, potentially associated with immunosuppression. We therefore conclude that while pentostatin is a safe and active agent for T-NHL regardless of CD26 expression, it may selectively deplete CD26+ T lymphocytes, with potentially significant clinical implications.

Adult↗