Durable Complete Remission and Long-Term Survival in FDG-PET Staged Patients with Stage III Follicular Lymphoma, Treated with Wide-Field Radiation Therapy.

Advanced-stage follicular lymphoma (FL) is generally considered incurable with conventional systemic therapies, but historic series describe long-term disease-free survival in stage III disease treated with wide-field radiation therapy (WFRT), encompassing all known disease sites. We report outcomes for patients staged with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and treated with CT-planned WFRT, given as either comprehensive lymphatic irradiation (CLI) or total nodal irradiation (TNI). This analysis of a prospective cohort includes PET-staged patients given curative-intent WFRT as a component of initial therapy, or as sole treatment for stage III FL. Thirty-three PET-staged patients with stage III FL received WFRT to 24-30Gy between 1999 and 2017. Fifteen patients also received planned systemic therapy (containing rituximab in 11 cases) as part of their primary treatment. At 10 years, overall survival and freedom from progression (FFP) were 100% and 75%, respectively. None of the 11 rituximab-treated patients have relapsed. Nine relapses occurred; seven patients required treatment, and all responded to salvage therapies. A single death occurred at 16 years. The principal acute toxicity was transient hematologic; one patient had residual grade two toxicity at one year. With FDG-PET staging, most patients with stage III FL experience prolonged FFP after WFRT, especially when combined with rituximab.

Lack of Durable Remission with Conventional-Dose Total Skin Electron Therapy for the Management of Sezary Syndrome and Multiply Relapsed Mycosis Fungoides.

Mycosis fungoides (MF) and Sezary syndrome (SS) are multi-relapsing, morbid, cutaneous T-cell lymphomas. Optimal treatment sequencing remains undefined. Total skin electron therapy (TSE) is a highly technical, skin-directed treatment, uniquely producing symptom-free and treatment-free intervals. Recent publications favour low-dose TSE for reduced toxicity, but early data support conventional-dose TSE (cdTSE) for longer disease control. Patient selection requires weighing-up tolerability against response durability. We investigated duration of benefit from cdTSE in patients with poorer prognosis diseases: SS and heavily pre-treated MF. Endpoints were overall survival, and "time to next treatment" (TTNT) as surrogate for clinical benefit duration. Seventy patients (53 MF, 17 SS) were eligible: median prior treatments, 4; median cdTSE dose, 30 Gy; median follow-up, 5.8 years. SS patients had worse prognosis (HR = 5.0, p < 0.001) and shorter TTNT (HR = 4.5, p < 0.001) than MF patients; median TTNT was only 3.7 months. Heavily pre-treated MF patients had inferior prognosis (HR = 1.19 per additional line, p = 0.005), and shorter TTNT (HR = 1.13 per additional line, p = 0.031). Median TTNT for MF patients with ≥3 prior treatments was 7.1 months, versus 23.2 months for 0-2 prior treatments. In conclusion, cdTSE has a limited role in SS. TTNT is reduced in heavily pre-treated MF patients, suggesting greater benefit when utilized earlier in treatment sequencing.

Health-related quality of life in patients with high-risk low-grade glioma (EORTC 22033-26033): a randomised, open-label, phase 3 intergroup study.

BACKGROUND: Temozolomide chemotherapy versus radiotherapy in patients with a high-risk low-grade glioma has been shown to have no significant effect on progression-free survival. If these treatments have a different effect on health-related quality of life (HRQOL), it might affect the choice of therapy. We postulated that temozolomide compromises HRQOL and global cognitive functioning to a lesser extent than does radiotherapy. METHODS: We did a prospective, phase 3, randomised controlled trial at 78 medical centres and large hospitals in 19 countries. We enrolled adult patients (aged ≥18 years) with histologically confirmed diffuse (WHO grade II) astrocytoma, oligodendroglioma, or mixed oligoastrocytoma, with a WHO performance status of 2 or lower, without previous chemotherapy or radiotherapy, who needed active treatment other than surgery. We randomly assigned eligible patients (1:1) using a minimisation technique, stratified by WHO performance status (0-1 vs 2), age (<40 years vs ≥40 years), presence of contrast enhancement on MRI, chromosome 1p status (deleted vs non-deleted vs indeterminate), and the treating medical centre, to receive either radiotherapy (50·4 Gy in 28 fractions of 1·8 Gy for 5 days per week up to 6·5 weeks) or temozolomide chemotherapy (75 mg/m2 daily, for 21 of 28 days [one cycle] for 12 cycles). The primary endpoint was progression-free survival (results published separately); here, we report the results for two key secondary endpoints: HRQOL (assessed using the European Organisation for Research and Treatment of Cancer's [EORTC] QLQ-C30 [version 3] and the EORTC Brain Cancer Module [QLQ-BN20]) and global cognitive functioning (assessed using the Mini-Mental State Examination [MMSE]). We did analyses on the intention-to-treat population. This study is closed and is registered at EudraCT, number 2004-002714-11, and at ClinicalTrials.gov, number NCT00182819. FINDINGS: Between Dec 6, 2005, and Dec 21, 2012, we randomly assigned 477 eligible patients to either radiotherapy (n=240) or temozolomide chemotherapy (n=237). The difference in HRQOL between the two treatment groups was not significant during the 36 months' follow-up (mean between group difference [averaged over all timepoints] 0·06, 95% CI -4·64 to 4·75, p=0·98). At baseline, 32 (13%) of 239 patients who received radiotherapy and 32 (14%) of 236 patients who received temozolomide chemotherapy had impaired cognitive function, according to the MMSE scores. After randomisation, five (8%) of 63 patients who received radiotherapy and three (6%) of 54 patients who received temozolomide chemotherapy and who could be followed up for 36 months had impaired cognitive function, according to the MMSE scores. No significant difference was recorded between the groups for the change in MMSE scores during the 36 months of follow-up. INTERPRETATION: The effect of temozolomide chemotherapy or radiotherapy on HRQOL or global cognitive functioning did not differ in patients with low-grade glioma. These results do not support the choice of temozolomide alone over radiotherapy alone in patients with high-risk low-grade glioma. FUNDING: Merck Sharp & Dohme-Merck & Co, National Cancer Institute, Swiss Cancer League, National Institute for Health Research, Cancer Research UK, Canadian Cancer Society Research Institute, National Health and Medical Research Council, European Organisation for Research and Treatment of Cancer Cancer Research Fund.

Temozolomide chemotherapy versus radiotherapy in high-risk low-grade glioma (EORTC 22033-26033): a randomised, open-label, phase 3 intergroup study.

BACKGROUND: Outcome of low-grade glioma (WHO grade II) is highly variable, reflecting molecular heterogeneity of the disease. We compared two different, single-modality treatment strategies of standard radiotherapy versus primary temozolomide chemotherapy in patients with low-grade glioma, and assessed progression-free survival outcomes and identified predictive molecular factors. METHODS: For this randomised, open-label, phase 3 intergroup study (EORTC 22033-26033), undertaken in 78 clinical centres in 19 countries, we included patients aged 18 years or older who had a low-grade (WHO grade II) glioma (astrocytoma, oligoastrocytoma, or oligodendroglioma) with at least one high-risk feature (aged >40 years, progressive disease, tumour size >5 cm, tumour crossing the midline, or neurological symptoms), and without known HIV infection, chronic hepatitis B or C virus infection, or any condition that could interfere with oral drug administration. Eligible patients were randomly assigned (1:1) to receive either conformal radiotherapy (up to 50·4 Gy; 28 doses of 1·8 Gy once daily, 5 days per week for up to 6·5 weeks) or dose-dense oral temozolomide (75 mg/m2 once daily for 21 days, repeated every 28 days [one cycle], for a maximum of 12 cycles). Random treatment allocation was done online by a minimisation technique with prospective stratification by institution, 1p deletion (absent vs present vs undetermined), contrast enhancement (yes vs no), age (<40 vs ≥40 years), and WHO performance status (0 vs ≥1). Patients, treating physicians, and researchers were aware of the assigned intervention. A planned analysis was done after 216 progression events occurred. Our primary clinical endpoint was progression-free survival, analysed by intention-to-treat; secondary outcomes were overall survival, adverse events, neurocognitive function (will be reported separately), health-related quality of life and neurological function (reported separately), and correlative analyses of progression-free survival by molecular markers (1p/19q co-deletion, MGMT promoter methylation status, and IDH1/IDH2 mutations). This trial is closed to accrual but continuing for follow-up, and is registered at the European Trials Registry, EudraCT 2004-002714-11, and at ClinicalTrials.gov, NCT00182819. FINDINGS: Between Sept 23, 2005, and March 26, 2010, 707 patients were registered for the study. Between Dec 6, 2005, and Dec 21, 2012, we randomly assigned 477 patients to receive either radiotherapy (n=240) or temozolomide chemotherapy (n=237). At a median follow-up of 48 months (IQR 31-56), median progression-free survival was 39 months (95% CI 35-44) in the temozolomide group and 46 months (40-56) in the radiotherapy group (unadjusted hazard ratio [HR] 1·16, 95% CI 0·9-1·5, p=0·22). Median overall survival has not been reached. Exploratory analyses in 318 molecularly-defined patients confirmed the significantly different prognosis for progression-free survival in the three recently defined molecular low-grade glioma subgroups (IDHmt, with or without 1p/19q co-deletion [IDHmt/codel], or IDH wild type [IDHwt]; p=0·013). Patients with IDHmt/non-codel tumours treated with radiotherapy had a longer progression-free survival than those treated with temozolomide (HR 1·86 [95% CI 1·21-2·87], log-rank p=0·0043), whereas there were no significant treatment-dependent differences in progression-free survival for patients with IDHmt/codel and IDHwt tumours. Grade 3-4 haematological adverse events occurred in 32 (14%) of 236 patients treated with temozolomide and in one (<1%) of 228 patients treated with radiotherapy, and grade 3-4 infections occurred in eight (3%) of 236 patients treated with temozolomide and in two (1%) of 228 patients treated with radiotherapy. Moderate to severe fatigue was recorded in eight (3%) patients in the radiotherapy group (grade 2) and 16 (7%) in the temozolomide group. 119 (25%) of all 477 patients had died at database lock. Four patients died due to treatment-related causes: two in the temozolomide group and two in the radiotherapy group. INTERPRETATION: Overall, there was no significant difference in progression-free survival in patients with low-grade glioma when treated with either radiotherapy alone or temozolomide chemotherapy alone. Further data maturation is needed for overall survival analyses and evaluation of the full predictive effects of different molecular subtypes for future individualised treatment choices. FUNDING: Merck Sharpe & Dohme-Merck & Co, Canadian Cancer Society, Swiss Cancer League, UK National Institutes of Health, Australian National Health and Medical Research Council, US National Cancer Institute, European Organisation for Research and Treatment of Cancer Cancer Research Fund.

Lack of durable disease control with chemotherapy for mycosis fungoides and Sézary syndrome: a comparative study of systemic therapy.

Numerous systemic treatment options exist for patients with mycosis fungoides (MF) and Sézary syndrome (SS), but no large comparative studies are published. To study the efficacy of treatments, a retrospective analysis of our cutaneous lymphoma database was undertaken, with 198 MF/SS patients undergoing systemic therapies. The primary end point was time to next treatment (TTNT). Patients with advanced-stage disease made up 53%. The median follow-up time from diagnosis for all alive patients was 4.9 years (range 0.3-39.6), with a median survival of 11.4 years. Patients received a median of 3 lines of therapy (range 1-13), resulting in 709 treatment episodes. Twenty-eight treatment modalities were analyzed. The median TTNT for single- or multiagent chemotherapy was only 3.9 months (95% confidence interval [CI] 3.2-5.1), with few durable remissions. α-interferon gave a median TTNT of 8.7 months (95% CI 6.0-18.0), and histone deacetylase inhibitors (HDACi) gave a median TTNT of 4.5 months (95% CI 4.0-6.1). When compared directly with chemotherapy, interferon and HDACi both had greater TTNT (P < .00001 and P = .01, respectively). This study confirms that all chemotherapy regimens assessed have very modest efficacy; we recommend their use be restricted until other options are exhausted.

Efficacy of low dose radiotherapy for primary orbital marginal zone lymphoma.

Marginal zone lymphoma (MZL) is a radiosensitive tumor, with high local control (LC) rates with moderate dose radiotherapy (RT). This retrospective study, performed at the Peter MacCallum Cancer Centre, evaluated the efficacy and toxicity of patients with orbital MZL treated to 24-25 Gy. Twenty-four patients (27 orbits) were identified, with median follow-up of 41 months. Disease was conjunctival in 16 orbits (59%), lacrimal in seven (26%), in the eyelid in one (4%) and elsewhere in three (11%). All patients attained a complete response. Three patients had treatment failures: one local relapse, one contralateral and one distant relapse. Freedom from local failure, freedom from progression, progression-free survival and overall survival were 100%, 90%, 90% and 100% at 2 years and 92%, 81%, 81% and 100% at 5 years, respectively. Aside from cataractogenesis, there was no significant late toxicity. Our study shows that RT doses of 24-25 Gy provide high rates of LC for orbital MZL with acceptable morbidity.

The addition of temozolomide does not change the pattern of progression of glioblastoma multiforme post-radiotherapy.

INTRODUCTION: To determine whether the pattern of progressive disease (PD) for glioblastoma multiforme (GBM) patients has changed with the introduction of the current standard of care protocol - postoperative conformal radiotherapy to a dose of 60 Gray in 30 fractions with concurrent low-dose (75-100 mg/m(2) ) temozolomide, followed by six cycles of adjuvant high-dose (150-200 mg/m(2) ) temozolomide - as compared with radiotherapy alone. METHODS: For GBM patients commencing combined modality treatment between October 2005 and August 2009, the MRI scan confirming progression (if any) was co-registered with the original planning CT scan, and progression site(s) marked. Coverage of the composite progression volume (PDvol) by the original 95% prescription isodose volume was obtained from dose-volume histogram (DVH) data, and assigned as 'central', 'in field', 'marginal' and 'out of field', corresponding to >95%, >80%, 20-80% and <20% coverage. RESULTS: Of 68 consecutive patients identified, 54 (79.4%) had documented PD. Of the 47 (87%) evaluable patients, 43 (91%) had in field progression with 36 (77%) of these being central. Of the remaining four cases, three (6%) had marginal progression, and only one patient (2%) had out of field progression. Median overall and progression-free survival were 11.6 and 6.6 months, respectively. CONCLUSION: The pattern of progression in our GBM patients does not appear to have been altered by the addition of temozolomide. The overwhelming majority of first PD occurred within the original radiotherapy planning target volume, as is the case in patients treated with radiotherapy alone. Major changes to radiotherapy volumes are not indicated, with alternative strategies required to improve outcomes.

Early post-treatment pseudo-progression amongst glioblastoma multiforme patients treated with radiotherapy and temozolomide: a retrospective analysis.

INTRODUCTION: To evaluate the incidence and impact of early post-chemoradiation (cRT) 'pseudoprogression' (PsPD) amongst glioblastoma multiforme (GBM) patients treated with the current standard of care - 60 Gy conformal radiotherapy with concurrent low-dose temozolomide, followed by six cycles of high-dose temozolomide (the 'Stupp protocol'). METHODS: Clinical notes and radiology reports for GBM patients treated as per the Stupp protocol were reviewed. PsPD was defined as apparent radiological progression on the first post-cRT scan, with further imaging within 3 months being stable or improving, while true early progression (ePD) was confirmed by continued progression in the subsequent 3 months following the first post-cRT scan. RESULTS: Of the 68 patients evaluated, 14 (21%) and 27 (40%) experienced PsPD and ePD, respectively; 3/14 (21%) patients experiencing PsPD and 14/27(52%), ePD were symptomatic for progression on first post-cRT follow-up (P = 0.096 for difference). Median survival for patients with ePD, PsPD and neither were 10.4, 27.4 and 13.0 months, respectively (P = 0.003 for ePD vs. PsPD, P = 0.19 for neither vs. PsPD groups). CONCLUSION: These data confirm a significant incidence of PsPD in post-cRT GBM patients, associated with improved median survival compared with those with neither ePD nor PsPD (not statistically significant). It appears likely that PsPD actually represents tumour response, conflicting with the traditional notion that increase in lesion size on contrast-enhanced imaging represents disease progression. Early post-cRT imaging should thus be interpreted with caution. Accompanying clinical symptoms are more commonly associated with ePD, but do not reliably distinguish PsPD from ePD.

A transesophageal echocardiography examination clarifies the cause of cardiovascular collapse during scoliosis surgery in a child.

PURPOSE: The prone position is required for posterior spinal fusion surgery and may be associated with cardiovascular changes, including a decrease in venous return and cardiac index. We report a case of a patient who developed cardiovascular collapse, increased central venous pressure (CVP), and massive bleeding during posterior spinal fusion surgery. A transesophageal echocardiography examination (TEE) documented a right ventricular outflow tract (RVOT) obstruction associated with the use of transverse bolsters. CLINICAL FEATURES: We describe a case of a healthy 14-yr-old male with idiopathic scoliosis who developed severe intraoperative cardiovascular instability and massive bleeding. The surgery was suspended, and the patient was transferred to the intensive care unit. The patient subsequently underwent TEE in the supine and prone positions. The echocardiogram appeared normal in the supine position; however, in the prone position with transverse bolsters, we identified a significant decrease in the diameter of the RVOT that worsened with pressure applied against the thoracic spine. The central venous pressure increased from 10-24 mmHg simultaneously. We found appreciably less impact to the RVOT, RV size and flow, and CVP (10 to 14 mmHg) using longitudinal bolsters both with and without pressure to the back. This position was recommended for the patient's reoperation, which was uneventful. CONCLUSION: A TEE confirmed a RVOT obstruction in the prone position that was associated, in this case, with the use of transverse bolsters. The RVOT obstruction was explained by the chest deformity, compliant chest cage, bolstering, and pressure applied to the patient's back by the surgeon. This positional RVOT obstruction may explain the increase in the CVP and the secondary massive bleeding during the first operation. The TEE was useful to diagnose the patient's condition and to guide his positioning for the second operation.

Comparative PET study using F-18 FET and F-18 FDG for the evaluation of patients with suspected brain tumour.

The aim of this prospective pilot study in patients with suspected or known brain tumour was to establish the diagnostic value of O-(2-[(18)F]-fluoroethyl)-L-tyrosine (FET) positron emission tomography (PET) when compared to fluorine-18 fluorodeoxyglucose (FDG) PET. Twenty-five FET PET and FDG PET scans were performed on 21 consecutive patients within 24 months. Final malignant pathology included 11 glioma (eight low-grade, three high grade), two lymphoma, one olfactory ganglioneuroblastoma, one anaplastic meningioma. Benign pathology included two encephalitis and one cortical dysplasia. Definitive pathology was not available in three patients. The accuracy of PET was determined by subsequent surgical histopathology in 12 and clinical/imaging course in nine patients. Median follow-up period was 20 months. FET sensitivity was 93%, specificity 100%, accuracy 96%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91%. FDG sensitivity was 27%, specificity 90%, accuracy 52%, PPV 80% and NPV 45%. FET PET is more accurate than FDG PET for detecting malignant brain lesions, especially low-grade gliomas.

Mantle cell lymphoma with central nervous system involvement: frequency and clinical features.

Reported rates of central nervous system (CNS) involvement in mantle cell lymphoma (MCL) are highly variable but substantial (4-26%). Data is lacking regarding risk factors for CNS relapse, and for those patients in whom CNS prophylaxis could be beneficial. We present single institution retrospective analysis of data of baseline features, clinical course, rate of CNS disease and putative risk factors in 62 patients with MCL (18 female, 44 male). CNS disease (all cases were symptomatic) occurred in four patients at a median of 12 months (range 1-58) from diagnosis, with a crude incidence of 6.5% and 5-year actuarial incidence of 5 +/- 3%. Two cases had blastic MCL at diagnosis. Survival after CNS relapse ranged from 2-9 months. Patients who developed CNS disease had a significantly shorter survival from diagnosis than those who did not (P = 0.0024). Symptomatic CNS disease in patients with MCL either at presentation or relapse is an uncommon but devastating complication. In younger patients, more aggressive immuno-chemotherapy regimens containing CNS-penetrating agents may reduce the incidence of CNS disease. While not routinely justified for all patients, CNS prophylaxis may particularly benefit patients with blastic histology at diagnosis, or those with systemic relapse after first-line treatment.

Impact of 18F-fluorodeoxyglucose positron emission tomography before and after definitive radiation therapy in patients with apparently solitary plasmacytoma.

PURPOSE: To evaluate the impact of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) on management of patients with apparently isolated plasmacytoma. METHODS AND MATERIALS: Twenty-one patients with apparently solitary plasmacytoma who underwent FDG-PET for staging or restaging were identified from a central PET database. They were either candidates for or had received definitive radiation therapy (RT). RESULTS: Seventeen patients had initial staging scans for bone (n = 11) or soft tissue (n = 6) plasmacytomas, and 11 had PET scans after RT. Only 1 of 14 known untreated sites of plasmacytoma was not identified on staging PET (lesion sensitivity = 93%). Three plasmacytomas were excised before PET. Staging PET influenced management in 6 of 17 patients (35%) by showing multiple myeloma (n = 1), discouraging RT after complete resection (n = 1), excluding plasmacytoma at a second site (n = 1), by increasing RT fields (n = 2), or by suggesting sarcoidosis (n = 1). Fifteen of 17 patients with initial staging PET scans received definitive RT. Restaging PET scans after RT showed complete metabolic response in 8 of 11 cases and progressive disease in 2. Two patients with either no response or partial metabolic response had late responses. Staging sestamibi and PET scans were concordant in five of six occasions (one sestamibi scan was false negative). CONCLUSIONS: FDG-PET has value for staging and RT planning in plasmacytoma and potentially could have a role in response-assessment after RT. Slow resolution of FDG uptake posttreatment does not necessarily imply an adverse prognosis.

Long-term outcomes of patients with advanced-stage cutaneous T-cell lymphoma and large cell transformation.

Although mycosis fungoides (MF) is typically an indolent disease, patients with advanced-stage disease (stages IIB-IVB), including Sézary syndrome (SS), often have a poor outcome. A 31-year, retrospective analysis of our cutaneous lymphoma database, of 297 patients with MF and SS, was undertaken to study long-term outcomes and identify clinical predictors of outcome in patients with advanced-stage disease (ASD, n = 92) and large cell transformation (LCT, n = 22). Two-thirds of patients with ASD presented with de novo ASD. The median overall survival (OS) for ASD was 5 years with a 10-year predicted OS of 32%. Age at initial diagnosis (P = .01), tumor stage (P = .01), and clinical stage (P = .001) were found to be significant predictors of outcome. Patients who presented with de novo ASD demonstrated better outcomes that were not statistically significant than those with a prior diagnosis of early-stage MF (P = .25). Transformation developed in 22 of the 297 MF/SS patients (7.4%), with a transformation rate of only 1.4% in patients with early-stage disease, compared with stage IIB (27%) and stage IV (56%-67%) disease. The median OS from diagnosis of LCT was 2 years. We confirm that the incidence of LCT is strongly dependent on tumor stage at diagnosis, and we demonstrate a much lower overall risk of LCT than previously reported.

Extracorporeal photopheresis for the treatment of Sézary syndrome using a novel treatment protocol.

Various studies have reported that extracorporeal photopheresis is effective in producing meaningful responses in patients with Sézary syndrome. A single-center, 5-year retrospective analysis was performed on our patients with Sézary syndrome who received extracorporeal photopheresis using a novel protocol. Thirteen patients were treated with extracorporeal photopheresis consistently for a minimum of 2 months. All patients received a modified protocol of one treatment per week for 6 sessions, one session every 2 weeks for 6 sessions, and then one session per month. The overall response rate was 62%: two patients achieved a complete response and 6 patients achieved a partial response. The median time to response was 10 months. The 2- and 4-year predicted overall survivals were 82%. This study was limited by its retrospective nature and small sample size. Response and survival compare favorably with those of previous studies. Our modified treatment protocol appears to produce outcomes similar to the two-day protocol.

Histone deacetylase inhibitor panobinostat induces clinical responses with associated alterations in gene expression profiles in cutaneous T-cell lymphoma.

PURPOSE: Histone deacetylase inhibitors can alter gene expression and mediate diverse antitumor activities. Herein, we report the safety and activity of the histone deacetylase inhibitor panobinostat (LBH589) in cutaneous T-cell lymphoma (CTCL) and identify genes commonly regulated by panobinostat. EXPERIMENTAL DESIGN: Panobinostat was administered orally to patients with CTCL on Monday, Wednesday, and Friday of each week on a 28-day cycle. A dose of 30 mg was considered excessively toxic, and subsequent patients were treated at the expanded maximum tolerated dose of 20 mg. Biopsies from six patients taken 0, 4, 8, and 24 h after administration were subjected to microarray gene expression profiling and real-time quantitative PCR of selected genes. RESULTS: Patients attained a complete response (n = 2), attained a partial response (n = 4), achieved stable disease with ongoing improvement (n = 1), and progressed on treatment (n = 2). Microarray data showed distinct gene expression response profiles over time following panobinostat treatment, with the majority of genes being repressed. Twenty-three genes were commonly regulated by panobinostat in all patients tested. CONCLUSIONS: Panobinostat is well tolerated and induces clinical responses in CTCL patients. Microarray analyses of tumor samples indicate that panobinostat induces rapid changes in gene expression, and surprisingly more genes are repressed than are activated. A unique set of genes that can mediate biological responses such as apoptosis, immune regulation, and angiogenesis were commonly regulated in response to panobinostat. These genes are potential molecular biomarkers for panobinostat activity and are strong candidates for the future assessment of their functional role(s) in mediating the antitumor responses of panobinostat.