NCI 9938: Phase I clinical trial of ATR inhibitor berzosertib (M6620, VX-970) in combination with irinotecan in patients with advanced solid tumors

3012

Background: Ataxia telangiectasia and Rad3 related (ATR) is activated in response to replication stress from topoisomerase 1 inhibitors. Selective ATR inhibition with berzosertib potentiates the efficacy of irinotecan in colorectal mouse xenograft models. We hypothesized that berzosertib in combination with irinotecan is well tolerated, modulates the DNA damage repair response to irinotecan, and the combination is associated with clinical activity. Methods: This phase I study utilized a modified Storer’s up and down dose escalation design. Dose Levels (DLs) combined berzosertib 60 to 270 mg/m2 with irinotecan 180 mg/m2, every 2 weeks in a 4-week cycle. The primary endpoint was identification of the maximum tolerated dose (MTD) and recommended phase II dose (RP2D). Activity, pharmacokinetics (PK), and pharmacodynamics (PD) were secondary endpoints. The identification of molecular subpopulations sensitized to the combination was exploratory. Results: Between July 2016 and July 2021, 51 patients (pts) enrolled, of whom 50 received treatment. Pts most commonly had colorectal cancer (CRC, 39%), pancreatic cancer (24%), small cell lung cancer (SCLC, 6%) and non-small cell lung cancer (6%). The median number of prior lines of therapy was 4 (range, 2 to 11). In Stage I, 1 of 3 evaluable pts experienced dose-limiting toxicity (DLT) of grade 3 lung infection at DL3 (berzosertib 180 mg/m2 - irinotecan 180 mg/m2), and Stage II was initiated enrolling cohorts of 5 pts. In Stage II, 4 of the first 11 pts treated at DL4 (berzosertib 270 mg/m2 - irinotecan 180 mg/m2) were unable to complete the DLT evaluation period due to clinically significant toxicity not meeting DLT criteria: grade 2 diarrhea (1 pt), grade 3 diarrhea (1 pt), and grade 3 neutrophil decrease (2 pts). The protocol was amended to limit dose escalation beyond DL4. At DL4, 1 of 21 evaluable pts experienced DLT (grade 4 febrile neutropenia). Most common treatment-related grade ≥ 3 toxicities were neutrophil decrease (34%), lymphocyte decrease (30%), WBC decrease (28%), anemia (20%), diarrhea (16%), fatigue (8%) and hypokalemia (8%). 2 partial responses were observed, occurring in pts with pancreatic cancer and ATM alterations: 32% decrease in an ATM E11828/ATM K1109* tumor lasting 15.3 months and 68% decrease in an ATM R3008H/germline ATM R1882* tumor ongoing at 11 months. An additional pt with ATM S214fs*40 mutant colorectal cancer (CRC) experienced a 26% decrease lasting 7.5 months. Conclusions: Berzosertib 270 mg/m2 - irinotecan 180 mg/m2 was declared the RP2D. The combination is associated with manageable side effects and promising disease activity in ATM mutant solid tumors. PK and PD studies are in process. Tumor biopsy studies are planned in a 15 pt dose expansion cohort at DL4, enrolling pts with CRC, pancreatic cancer, SCLC and DNA damage repair deficient tumors. Clinical trial information: NCT02595931.

Determining the prevalence and risk factors for prescription drug unaffordability

BACKGROUND

Prescription affordability is a key component of healthcare accessibility and a determinant of health outcomes. Prior studies indicate that up to 1 in 4 Americans report difficulty affording prescriptions.

OBJECTIVE(S)

This study aims to identify factors associated with cost-based prescription refusal.

METHODS

We identified 17,869 study participants from the 2017 National Health Interview Survey who had been prescribed at least one medication in the past 12 months. The outcome was defined as inability to afford at least one prescription medication. Covariates included demographic data, medical history, and social attitudes. Logistic regression models were constructed to identify predictors of cost-based prescription refusal.

RESULTS

Among 8223 study participants, 8.1% reported the inability to afford at least one prescription medication in the past 12 months. Twenty-seven covariates were correlated with prescription unaffordability, and 8 were selected by the LASSO: Income (Odds ratio (OR) 0.55), Concerned About Bills (OR 2.0), Emergency Department Visits past 12 months (OR 1.33), Dissatisfaction with Medical Care (OR 1.3), Seeking Insurance Through the Health Insurance Marketplace (OR 1.26), Feeling Sad Most of the Time (OR 1.24), History of Asthma (OR 1.26) and History of Diabetes (OR 1.24).

CONCLUSIONS

Prescription unaffordability remains a significant public health problem and is more common among low-income individuals and patients with, chronic medical conditions.

The effect of locality of residence (LOR) and socioeconomic status (SES) on mortality in patients with squamous cell carcinoma of the head and neck (HNSCC): 20-year experience at the UPMC Hillman Cancer Center

e19043

Background: As cancer centers expand, evaluation of potential disparities in outcomes amongst the catchment area is critically important. We examined the effect of LOR and SES on overall survival (OS) in HNSCC patients treated at HCC, which spans 29 counties in western Pennsylvania with diverse socioeconomic profiles across urban and rural localities. Methods: Retrospective review included patients with primary HNSCC (excluding M1 and recurrent disease) treated at HCC 1997-2018. Using Rural-Urban Commuting Area codes, LOR was classified as urban/suburban or rural according to ZIP code. SES was defined by medium income level (low, moderate (Mod), middle (Mid), Upper) via Federal Financial Institutions Examination Council geocoded census tract data. Kaplan-Meier methods and Cox regression models were used to evaluate OS. Results: 3512 patients were identified. Median age was 61, 72.7% male, 93.2% White, 18% HPV +, 75.5% urban/suburban, and by SES: 4% Low, 21% Mod, 46% Mid, and 19% Upper. Primary site included 35.2% oral cavity, 28.4% oropharynx, 28.1% larynx, 8.3% other, stage was majority III/IVa (61%), 66% had surgery and 54% received multimodality treatment (tx). While median OS differed significantly by race (Black: 5.8 vs. White: 7.3 years, p = 0.0457) and SES (Low: 4.1 vs. Mod: 5.3 vs. Mid: 7.3 vs. Upper: 9.1 years, p < 0.0001), there was no difference by LOR (rural: 7.7 vs. urban/suburban: 7.2 years, p = 0.99). Multivariable Cox Regression showed lower SES was associated with a higher risk of death [(Low vs. Upper, HR: 1.416, 95% CI: 1.023-1.959) (Mod vs. Upper, HR:1.443, 95% CI: 1.214 – 1.716), p = 0.0004], adjusting for LOR and factors associated with OS in univariate analysis (age, smoking status, primary site, staging, tx, HPV status, race, and enrollment on clinical trial). The effect of LOR, race, and enrollment on clinical trial were not significant in multivariate analysis. Conclusions: SES was independently associated with OS in HNSCC patients treated at HCC, while LOR was not associated with OS. The lack of difference by LOR may be partially explained by HCC’s efforts to increase access to care throughout the catchment area by establishing community sites. However, a focus on improving outcomes for lower SES HNSCC patients is needed.

Targeting autophagy and immunotherapy with hydroxychloroquine and interleukin 2 in patients with metastatic renal cell carcinoma (mRCC): A Cytokine Working Group study

106

Background: We performed a Phase II study of the combination of the autophagy inhibitor, hydroxychloroquine (HCQ), along with high dose IL-2 in patients with advanced renal cancer. 31 patients were entered on this Cytokine Working Group Study conducted at six member institutions;NCT01550367. This combination in murine models was associated with diminished toxicity and increased efficacy, and, in preliminary studies, diminished high mobility group box 1 (HMGB1) protein, consistent with its established role in serving as a Damage Associated Molecular Pattern (DAMP) molecule and inducer of autophagy. Methods: The Study Design involved initiating oral Hydroxychloroquine 300 mg P.O bid. Aldesleukin (600,000 IU/kg) was administered q8hrs in courses consisting of two cycles separated by 7-14 days and constituting a single course. For patients with stable or responsive disease, additional courses were administered every approximately 85-90 days. Serum, plasma, Paxgene tubes, and peripheral blood mononuclear cells were obtained sequentially prior to therapy initiation and sequentially on D1 and D2 of each cycle following initiation of therapy. Results: 31 patients (9F, 22M) have been registered and 3 confirmed complete responses observed; the current median overall survival has not been reached in the 29pts. The Baseline Karnofsky Score of 100 (17pts), 90 (13pts), and 80(1 pt). The mean age was 57.5 years, range = (45.2, 68.8). 26 patients had a mean of 12.5 doses +/-4.7 (3, 23) with 13 pts receiving a second course and 4, a third. Platelet nadir was diminished from baseline by 26%. Of the 27 patients in the data set, 18 had at least one Grade 4 toxicity at least possibly related to treatment, and 9 patients had at least one Grade 3 adverse event at least possibly related to treatment but no Grade 4 events.Serologic and cellular data and complete clinical data will be submitted with the completed abstract. Conclusions: The combination of high dose aldesleukin and daily oral HCQ was well tolerated. We have concluded this trial and will report mature survival data, toxicity data, and biomarkers/autophagy measures with the final submission. Clinical trial information: NCT01550367.

A phase 2 trial of regorafenib as a single agent in patients with chemotherapy refractory advanced and metastatic biliary adenocarcinoma/cholangiocarcinoma

4081

Background: Biliary adenocarcinoma/cholangiocarcinoma is a rare but aggressive neoplasm. Most patients present with unresectable or metastatic disease with 5-year survival rate ~5%. No second-line regimen has demonstrated clinical benefit in this disease. Regorafenib is an oral multi-kinase inhibitor with potent antitumor activity. This single arm phase II study evaluates the efficacy and safety of regorafenib as a single agent in advanced or metastatic biliary carcinoma/cholangiocarcinoma pts who failed systemic chemotherapy. Methods: Patients with ECOG PS 0-1and adequate liver, kidney and bone marrow function were given regorafenib orally once daily, 21 days on and 7 days off in a 28-day cycle. The initial dose of 160 mg was given to the first 3 patients. After toxicity assessment, the dose was reduced to 120 mg for the subsequent pts. The primary endpoint is PFS with the null hypotheses of 2.0 months, and median PFS ≥3.5 months as evidence of the study drug activity (α = 0.10, 80% power). Secondary objectives include OS, RR, and DCR. Results: Thirty-seven patients received at least one dose of regorafenib, of whom 28 were evaluable for efficacy. All had previous gemcitabine/cisplatin treatment. The mean age was 62.5 (34.5-82.8) with 17 (46%) females. PR was achieved in 3 (10.7%), SD in 18 (64.3%, with DCR of 75%), and PD in 7 (25%). For all 37 patients, median PFS was 3.55 months (95% CI = 2.1- 5.72) and mOS was 5.55 months (95% CI = 4.04 -NA) with survival rate of 42 % at 12 months, and 38% at 18 months. Medan PFS and OS of 30 patients who had ≥1 cycle were 3.91 months (95% CI = 3.55-9.79) and 13.4 months (95% CI = 5.06 - NA), respectively. The overall toxicity profile was as expected, with G3/4 AE’s of 40.5%. The most common toxicities were HTN, hypophosphatemia, hand-foot skin reaction, and increased serum bilirubin. Dose modification was required in 11 (30.6%) patients. Tumor samples were collected in 80% of patients, with planned correlative studies underway. Conclusions: This study showed promising efficacy of regorafenib in chemotherapy refractory advanced/metastatic cholangiocarcinoma. Further studies to confirm the clinic efficacy are recommended. Clinical trial information: NCT02053376.

Safety and preliminary activity of hydroxychloroquine and aldesleukin in metastatic renal cell carcinoma (mRCC): A cytokine working group study

440

Background: Aldesleukin (recombinant human interleukin-2) has been an FDA-approved treatment for mRCC since 1992, based on a 5-10% rate of durable complete remissions. Autophagy is a protective mechanism that enables cells to survive the metabolic stress of cancer therapy. Hydroxychloroquine (HCQ) inhibits cellular autophagy and has shown synergy with interleukin-2 in animal tumor models. We hypothesized that this combination would be tolerable and active in patients with mRCC. Methods: The Cytokine Working Group initiated a study of high-dose aldesleukin in combination with oral HCQ for patients with mRCC. Subjects receive up to 6 cycles of aldeskleukin, 600,000 International Units per kg, on a standard schedule. HCQ is administered orally starting 2 weeks prior to the first dose of aldesleukin and continuing up to one year. The initial HCQ dose was 600 mg daily, with a planned dose escalation to 1200 mg daily after safety was demonstrated in five subjects. Subjects were monitored for safety and tolerability as well as response per RECIST 1.1. Results: Five subjects were treated at the first dose level of 600 mg daily HCQ plus aldesleukin with no unexpected toxicity. Thirteen subjects were then treated at HCQ 1200 mg daily with aldesleukin. Of these, two experienced hypotension and tachycardia and 1 patient died from pulmonary emboli. The cardiac events were consistent with aldesleukin toxicity, but were observed earlier in the course of treatment than anticipated for aldesleukin alone. HCQ dose was therefore de-escalated to 600 mg daily, and 8 additional subjects have been enrolled with no unexpected toxicity. In 26 of 39 planned subjects, there has been 1 complete response (CR) and 1 partial response (near CR), both in the 600 mg cohort. As of Oct 24, 2016, after a median of 36.6 months of follow-up, seven out of 26 subject have died, with median overall survival not yet obtained (95% C.I. = (29.6 months,unknown)). Conclusions: HCQ in combination with aldesleukin was found to be tolerable at a dose of 600 mg daily, with expected toxicities. Clinical responses have been observed. Clinical trial information: NCT01550367.

Effect of 5-fluorouracil on membranous PD-L1 expression in colon cancer cells

592

Background: Colorectal cancer (CRC) is a major public health problem worldwide. Chemotherapy consisting of a fluoropyrimidine backbone constitutes a major therapeutic modality used in the treatment of CRC patients. However, cancer cells often develop resistance to such cytotoxic chemotherapy and this represents a major therapeutic challenge. B7-homolog 1 (B7-H1), also known as programmed death ligand-1 (PD-L1) is an immunoregulatory protein that belongs to the B7 family of T-cell co-regulatory molecules, and is overexpressed in several human tumors. Upregulation of PD-L1 expression is an important mechanism by which tumor cells can escape host T-cell immunity. Emerging evidence suggests that chemotherapeutic agents can regulate PD-L1 expression on cancer cells, which may have an impact on anti-tumor immunity and immune evasion. We performed this study to evaluate the effect of 5-Fluorouracil (5-FU) on PD-L1 expression in colon cancer cell lines, using an in vitro approach. Methods: Flow cytometry and western immunoblot analyses for PD-L1 expression were performed on human colon cancer cell lines (HCT116-WT, HCT116-p53 KO, SW480, HT29) upon treatment with IFN-ɣ and 5-FU. Results: We found that the tested human colon cancer cell lines rarely expressed PD-L1 protein on their cell surface at baseline, but a high level of expression was induced by treatment with IFN-ɣ. More importantly, we demonstrated that the chemotherapeutic agent 5-FU induces PD-L1 expression in colon cancer cells. Conclusions: It is therefore plausible that combining 5-FU with PD-1/PD-L1 blockade might help overcome some of the chemoresistance to 5-FU and thereby enhance its anti-cancer activity. Further experiments are being planned to formally test this hypothesis.

Has the paradigm changed away from lobectomy for stage I non-small cell lung cancer (NSCLC)? Anatomic segmentectomy: Surgery’s answer to image-guided ablation/radiation therapy for the small peripheral lung lesion

7577

Background: Lobectomy has been the “gold standard” for stage I NSCLC management. Image guided ablation/radiation therapy approaches are now being touted as alternatives to surgery despite concerns regarding diagnosis, pathologic staging, local control, and delayed toxicities. We evaluated the diagnostic utility and oncologic efficacy of lung sparing, anatomic segmentectomy for indeterminate pulmonary nodules and clinical stage I NSCLC. Methods: Retrospective review of 1,005 anatomic segmentectomies from 2002-2012 for indeterminate pulmonary nodules and clinical stage I NSCLC. Outcome variables included perioperative data, morbidity and mortality. Survival was assessed with the Kaplan-Maier method. Results: Mean age was 66.7 years. Median lesion size was 1.9 cm. VATS was employed in 62.8% of cases. Median operative time and blood loss was 112 minutes and 80 ml, respectively. Median hospital stay was 5 days. Major complications occurred in 12.7%. Thirty-day mortality was 1.0%. Of these, NSCLC was identified in 71.6%, metastases in 8.7%, and other benign conditions in 19.7%. Among patients with clinical stage I NSCLC, clinical: pathological upstaging was seen in 34.5%. Local recurrence rate was 5.2% and five-year freedom from any recurrence was 69%, equivalent to lobectomy in our experience. Conclusions: Anatomic segmentectomy is a valuable primary surgical approach today. In this era of competing image-guided ablation modalities, anatomic segmentectomy provides safety, diagnostic accuracy and adherence to oncologic surgical principles including completeness of resection with adequate surgical margins, systematic nodal staging improving pathologic accuracy, and tissue for pharmacogenomic assessment to guide individualized adjuvant therapy.

Rapid rational drug targeting of Merkel cell polyomavirus (MCV)-positive Merkel cell carcinoma (MCC) using the survivin inhibitor YM155

8577

Background: MCC is an aggressive, chemoresistant skin cancer causing more deaths each year than chronic myelogenous leukemia. We discovered a new virus, Merkel cell polyomavirus (MCV), clonally integrated into ~80% of primary and metastatic MCC in 2008. To find therapeutic targets for this cancer, we examined cellular genes perturbed by MCV infection. Methods: Digital transcriptome subtraction was used to discover MCV and also to reveal survivin gene (BIRC5) upregulation in virus-positive tumors. MCV T antigen knockdown studies in seven MCC lines and large T (LT) transduction into BJ fibroblasts were used to confirm this. Drug screening was performed in vitro using Cell-Titer Glo assays in a two stage analysis. In vivo screening used an MKL-1 (MCV+) MCC NOD-SCIDg mouse xenograft model with a single three-week treatment round. Results: MCV large T oncoprotein induces survivin transcription through retinoblastoma protein sequestration by the LT LXCXE motif. MCV T antigen knockdown results in nonapoptotic MCC cell death and loss of survivin expression. YM155, a phase II survivin transcription inhibitor, causes MCV+ MCC cell necroptosis associated with autophagy at 1-12 nM EC50. Of 1359 other drugs from LOPAC and NCI Oncology Set II libraries, only bortezomib had in vitro potency comparable to YM155. In MKL-1 xenograft studies, mice were treated with saline, bortezomib or YM155 for three weeks using standard dosings. Bortezomib did not significantly improve mouse survival (33%) over saline (24%) during treatment. In contrast, all YM155-treated mice survived (100%, p<0.001) the 3 week treatment period. Tumors resumed growth once YM155 treatment was stopped suggesting that YM155 is cytostatic in vivo rather than cytotoxic. Conclusions: Survivin expression is induced by MCV LT and is critical to MCV+ MCC survival. A survivin inhibitor, YM155 was nontoxic to mice and cytostatic for MCV+ MCC xenografts. Using genomic technologies, in less than four years, the primary viral cause for most MCC was discovered, new diagnostic tests developed and a promising rational drug candidate identified. A cooperative group trial (E1611) for YM155 and bortezomib in MCC patients is currently planned.

Anatomic segmentectomy versus lobectomy for clinical stage I non-small cell lung cancer: A propensity-matched analysis

7071

Background: Although anatomic segmentectomy is considered a “compromised” procedure by many surgeons, new information from several retrospective, single-institution series has countered negative premises regarding tumor recurrence and patient survival. The primary objective of this study was to utilize propensity score matching to compare outcomes following these anatomic resection approaches for stage I NSCLC. Methods: Patients undergoing lobectomy (n=392) vs. segmentectomy (n=793) for clinical stage I NSCLC were matched 1:1 using a propensity score that accounted for the potential confounding effects of pre-operative patient variables. Matching based on propensity scores produced 312 patients in each group. Primary outcome variables included recurrence-free and overall survival. Factors affecting survival were assessed by proportional hazards (Cox) regression and Kaplan-Meier survival function estimates. Results: Peri-operative mortality was 1.2% in the segmentectomy group and 2.5% in the lobectomy group (p=0.38). Ninety-day mortality was 2.6% and 4.8% (p=0.20), respectively. At a mean follow-up of 5.4 years, no differences were noted in locoregional (5.5% vs. 5.1%, p=1.00), distant (14.8% vs. 11.6%, p=0.29) or overall recurrence rates (20.2% vs. 16.7%, p=0.30) when comparing segmentectomy with lobectomy. Furthermore, no significant differences were noted in time to recurrence (p=0.415) or overall survival (p=0.258) when comparing the matched groups. Five year freedom from recurrence (95% CI) was: Segment 0.70 [95% CI: (0.63, 0.78) vs. Lobe 0.71 [95% CI: 0.64, 0.78]. Overall survival (95% CI) was: Segment 0.54 [95% CI: (0.47, 0.51) vs. Lobe 0.60 [95% CI: 0.54, 0.67]. Segmentectomy was not found to be an independent predictor of recurrence (HR: 1.11, 95% CI: 0.87, 1.40) or overall survival (HR = 1.17, 95% CI: 0.89.1.52). Conclusions: In this large propensity-matched comparison, anatomic segmentectomy is associated with similar time to recurrence and overall survival rates when compared to lobectomy for clinical stage I NSCLC. These results will need further validation by prospective, randomized trials (CALGB 140503).

Whole-liver irradiation with hepatic arterial floxuridine/leucovorin/streptozotocin followed by hepatic arterial floxuridine/leucovorin and chemo-embolization with mitomycin C for patients with metastatic neuroendocrine tumors

339

Background: Neuroendocrine tumors metastatic to liver are incurable with limited treatments. We conducted a phase I trial combining hepatic arterial (HA) chemotherapy, chemoembolization and dose-escalated whole liver radiotherapy (WLRT) to determine if the maximum safe dose of 32 Gy in 2 Gy fractions could be achieved.

Methods: Patients (pts) with liver metastases from neuroendocrine tumors who failed somatostatin analog therapy were eligible. First, floxuridine (FUDR, 3 mg/m2/d) and leucovorin (LV, 300 mg/m2/d) were given by continuous hepatic artery infusion for 12 days; streptozotocin (500 mg/m2/d) was given over 3 h on days 5, 8 and 10. Concurrent WLRT was prescribed in 2 Gy/day with doses escalated from 24 Gy to 32 Gy using the time-to-event continual reassessment method for dose allocation with a target rate of dose-limiting grade (gr.) ≥ 3 radiation-induced liver disease (RILD) of 10%. 8 weeks later, for pts without RILD and other gr. ≥ 4 toxicities, continuous 72-h infusion with HA FUDR (3 mg/m2/d) and LV (300 mg/m2/d) was given, followed by chemoembolization with mitomycin C (20 mg) and polyvinyl alcohol foam.

Results: 19 pts were enrolled in the trial. 8 pts received 24 Gy, 2 - 26 Gy, 1 - 28 Gy, 2 - 30 Gy and 6 - 32 Gy. 8 pts received only the first part of the treatment, 11 completed the entire protocol. No pts developed dose-limiting RILD; 5 - had gr. 3-4 increased liver function tests (LFT), 4 - had other gr. 4 toxicities after the first part of the treatment, primarily chemotherapy and embolization-related; 3 - had gr. 3 increased LFT, and 1 - had other gr. 4 toxicities after the second part of the treatment. 4 pts (21%) had partial response, 14 (74%) - stable disease and one pt (5%) receiving only part 1 had progressive disease. Median progression free survival for all pts was 20.6 (8.4-45.4) months (m); 15.4 (3.4-67.8) m for pts who received the first part of the treatment only, and 27.9 (8.4 – infinite) m for pts who received both parts of treatment.

Conclusions: This study showed that chemotherapy can be safely combined with a full dose of WLRT and subsequent chemoembolization without producing RILD.

Expression of 12-lipoxygenase as a biomarker for melanoma carcinogenesis

12-Lipoxygenase (12-LOX), through its metabolite 12( )-hydroxyeicosatetraenoic acid [12( )-HETE], has been demonstrated to play a pivotal role in experimental melanoma invasion and metastasis, and 12-LOX expression may be important in early human melanoma carcinogenesis. We have studied the differences in 12-LOX protein expression during the progression of melanoma from human melanocytic cells to benign and dysplastic naevi to malignant metastatic disease. 12-LOX expression was determined in normal human skin melanocytes and in melanocytes found in compound naevi, dysplastic naevi and melanomas using a platelet-type 12-LOX antibody with a diaminobenzidine immunoperoxidase system detection system and was quantified using the analysis software NIH Image 1.62. Mean cellular pixel densities for 12-LOX staining ( = 50 cells/histological type) were unchanged in compound naevi ( = 0.14) and were increased in dysplastic naevi and melanomas compared with normal skin melanocytes ( = 0.03 and = 0.01, respectively). Similarly, melanomas had higher levels of expression compared with dysplastic naevi ( = 0.03). 12-LOX expression was significantly different between compound naevus and dysplastic naevus melanocytes ( = 0.01). These data suggest that 12-LOX may be an important novel marker for cancer progression within the melanoma system, and therefore could be a useful biomarker and therapeutic target for melanoma chemoprevention.

Definition of the supraclavicular and infraclavicular nodes: implications for three-dimensional CT-based conformal radiation therapy

PURPOSE

To delineate with computed tomography (CT) the anatomic regions containing the supraclavicular (SCV) and infraclavicular (IFV) nodal groups, to define the course of the brachial plexus, to estimate the actual radiation dose received by these regions in a series of patients treated in the traditional manner, and to compare these doses to those received with an optimized dosimetric technique.

MATERIALS AND METHODS

Twenty patients underwent contrast material-enhanced CT for the purpose of radiation therapy planning. CT scans were used to study the location of the SCV and IFV nodal regions by using outlining of readily identifiable anatomic structures that define the nodal groups. The brachial plexus was also outlined by using similar methods. Radiation therapy doses to the SCV and IFV were then estimated by using traditional dose calculations and optimized planning. A repeated measures analysis of covariance was used to compare the SCV and IFV depths and to compare the doses achieved with the traditional and optimized methods.

RESULTS

Coverage by the 90% isodose surface was significantly decreased with traditional planning versus conformal planning as the depth to the SCV nodes increased (P < .001). Significantly decreased coverage by using the 90% isodose surface was demonstrated for traditional planning versus conformal planning with increasing IFV depth (P = .015). A linear correlation was found between brachial plexus depth and SCV depth up to 7 cm.

CONCLUSION

Conformal optimized planning provided improved dosimetric coverage compared with standard techniques.

Dose escalation in non-small-cell lung cancer using three-dimensional conformal radiation therapy: update of a phase I trial

PURPOSE

High-dose radiation may improve outcomes in non-small-cell lung cancer (NSCLC). By using three-dimensional conformal radiation therapy and limiting the target volume, we hypothesized that the dose could be safely escalated.

MATERIALS AND METHODS

A standard phase I design was used. Five bins were created based on the volume of normal lung irradiated, and dose levels within bins were chosen based on the estimated risk of radiation pneumonitis. Starting doses ranged from 63 to 84 Gy given in 2.1-Gy fractions. Target volumes included the primary tumor and any nodes >or= 1 cm on computed tomography. Clinically uninvolved nodal regions were not included purposely. More recently, selected patients received neoadjuvant cisplatin and vinorelbine.

RESULTS

At the time of this writing, 104 patients had been enrolled. Twenty-four had stage I, four had stage II, 43 had stage IIIA, 26 had stage IIIB, and seven had locally recurrent disease. Twenty-five received chemotherapy, and 63 were assessable for escalation. All bins were escalated at least twice. Although grade 2 radiation pneumonitis occurred in five patients, grade 3 radiation pneumonitis occurred in only two. The maximum-tolerated dose was only established for the largest bin, at 65.1 Gy. Dose levels for the four remaining bins were 102.9, 102.9, 84 and 75.6 Gy. The majority of patients failed distantly, though a significant proportion also failed in the target volume. There were no isolated failures in clinically uninvolved nodal regions.

CONCLUSION

Dose escalation in NSCLC has been accomplished safely in most patients using three-dimensional conformal radiation therapy, limiting target volumes, and segregating patients by the volume of normal lung irradiated.

Immunogenetic therapy of human melanoma utilizing autologous tumor cells transduced to secrete granulocyte-macrophage colony-stimulating factor

We performed a clinical study of five patients with melanoma to evaluate the immunobiological effects of retrovirally transduced autologous tumor cells given as a vaccine to prime draining lymph nodes. Patients were inoculated with both wild-type (WT) and GM-CSF gene-transduced tumor cells in different extremities. Approximately 7 days later, vaccine-primed lymph nodes (VPLNs) were removed. There was an increased infiltration of dendritic cells (DCs) in the GM-CSF-secreting vaccine sites compared with the WT vaccine sites. This resulted in a greater number of cells harvested from the GM-CSF-VPLNs compared with the WT-VPLNs at a time when serum levels of GM-CSF were not detectable. Four of five patients proceeded to have the adoptive transfer of GM-CSF-VPLN cells secondarily activated and expanded ex vivo with anti-CD3 MAb and IL-2. One patient had a durable complete remission of metastatic tumor. Utilizing cytokine (IFN-gamma, GM-CSF, IL-10) release assays, GM-CSF-VPLN T cells manifested diverse responses when exposed to tumor antigen in vitro. In two of two patients, GM-CSF-VPLN T cell responses were different from those of matched WT-VPLN cells. This study documents measurable immunobiologic differences of GM-CSF-transduced tumor cells given as a vaccine compared with WT tumor cells. The complete tumor remission in one patient provides a rationale to pursue this approach further.

Serum thyroglobulin levels after thyroxine withdrawal in patients with low risk papillary thyroid carcinoma

We hypothesized that elevated levels of serum thyroglobulin (Tg) are frequently found as the only index of residual neoplasm in patients with low-risk papillary thyroid carcinoma. The records of patients operated on for papillary thyroid carcinoma over a 2-year period were reviewed, and the patients were allocated to risk groups by a validated staging method that does not include Tg levels. Of the 35 patients who manifested a low-risk carcinoma, 9 (26%) exhibited elevated Tg concentrations (11-53 ng/mL) during thyroxine withdrawal after therapies, while clinical, scintigraphic, and radiographic studies at least 1 year later showed no evidence of tumor. Prior scintigraphic imaging of therapeutic doses of 131I in 8 of 9 patients demonstrated no distant metastases, further confirming the low-risk status of this group. The staging method predicts that only 0.9% of patients with low-risk papillary carcinoma will have a cause specific death in 20 years. Elevated Tg concentrations have not been shown to forecast independently the survival of patients with low-risk papillary carcinoma. Thus, although frequently encountered, elevated Tg concentrations are unlikely to predict shortened survival in patients with papillary carcinoma for whom low risk has been determined from other data.

Immunological effects of BCG as an adjuvant in autologous tumor vaccines

The role of Bacillus Colmette-Guérin (BCG) as an adjuvant in autologous tumor vaccines was examined. In nine patients with renal cell cancer, irradiated tumor cells alone (wild-type, WT) or with BCG were inoculated intradermally into contralateral thighs. Seven to 10 days later, the draining vaccine-primed lymph nodes (WT-VPLN and BCG-VPLN) were excised. BCG increased the number of harvested VPLN cells by 10-fold (mean +/- SE = 61.8 +/- 20.6/x10(-7)/patient). BCG-VPLN had significantly greater percentages of CD3(+) and CD4(+) T cells compared to WT-VPLN. Both groups of VPLN cells were activated in vitro with anti-CD3 or anti-CD3/CD28 mAbs followed by expansion in IL-2. Anti-CD3/CD28 activation resulted in greater expansion of CD4(+) T cells compared to anti-CD3. After activation, VPLN cells were stimulated with irradiated autologous tumor targets and cytokines (IFN-gamma, GM-CSF, IL-10) released into the supernatants were measured 24 h later. Anti-CD3/CD28-activated BCG-VPLN cells were found to have a greater release of IFN-gamma compared with that of WT-VPLN cells, which was not observed significantly with IL-10 or GM-CSF. BCG resulted in increased VPLN cell yield as well as enhanced type 1 (IFN-gamma release) immune responses of VPLN cells to autologous tumor without upregulating type 2 (IL-10 release) responses. Anti-CD3/CD28 was superior to anti-CD3 activation in this cellular response.

The multidisciplinary melanoma clinic: a cost outcomes analysis of specialty care

The traditional process of melanoma care delivery can differ substantially among providers regarding screening laboratories, staging work-ups, surgical margins, and outpatient versus inpatient surgical management. It has been suggested that multidisciplinary care may provide a more cost-effective management approach. We sought to evaluate whether coordinated multidisciplinary melanoma care that follows evidence-based, consensus-approved clinical practice guidelines at a large academic medical center can provide a more efficient alternative to traditional community-based strategies with clinical outcomes that are at least equivalent. The University of Michigan Multidisciplinary Melanoma Clinic (MDMC) possesses a database of demographic, clinical, and treatment information for all patients seen since its inception. A consecutive sample of 104 patients with local disease who were treated in the Michigan community were compared with 104 blindly selected subjects treated at the MDMC during an identical time period, matched for Breslow depth and melanoma body site. Patients treated in the MDMC would save a third party payer roughly $1600 per patient when compared with a similar group treated in the Michigan community. Surgical morbidity, length of hospitalization, and long-term survival of MDMC patients were similar to those reported in the literature. The cost discrepancy is explained by the fundamental differences in the usage pattern of health care resources exhibited by the MDMC compared with the community setting.

A novel approach to assess changes in endocrine secretion: analysis of GnRH antagonist (Nal-Glu) suppression of gonadotropin release in ovariectomized ewes

Circulating hormone levels reflect the outcome of multiple feedback systems. A method to accurately assess the dynamics of hormonal changes in samples collected at infrequent intervals and compare these dynamic processes among treatment groups is presented. In this approach, a smooth curve is fitted to each time series of concentrations produced in an experiment, the curves are summarized by numerical measurements, and the measurements are subjected to statistical analysis. The method is demonstrated on data from an experiment that explores the differential effects of a competitive GnRH receptor antagonist (Nal-Glu) on circulating levels of LH and FSH. In this experiment, six adult ovariectomized Suffolk ewes were treated with one of three doses of Nal-Glu using a crossover design. LH and FSH concentrations were determined in hourly samples of jugular blood for 24 h after treatment. Applying the analytical approach, we observed differential effects of increasing concentrations of Nal-Glu on circulating LH and FSH concentrations. The magnitude of LH suppression was similar from dose to dose, while the duration of LH suppression was dose-dependent. In contrast, all doses of Nal-Glu elicited similar effects on the amplitude, duration and time to recovery of FSH suppression. Studies conducted in vitro utilizing dispersed ovine pituitary cells in culture demonstrated that the differential effects of Nal-Glu on FSH and LH secretion were not the outcome of differential sensitivity of FSH and LH to GnRH. The differential effects of Nal-Glu on circulating LH and FSH concentrations may be due to a number of factors, including other releasing or release-inhibiting hormones, paracrine modulators involved in selective regulation of FSH, and/or differences in clearances.

Adoptive immunotherapy with vaccine-primed lymph node cells secondarily activated with anti-CD3 and interleukin-2

PURPOSE

In preclinical studies, we have reported the ability to induce immune T cells in lymph nodes (LN) primed by in vivo vaccination with tumor cells admixed with a bacterial adjuvant. These LN cells can be activated and expanded ex vivo for the successful immunotherapy of established tumors. We have applied these methods to generate vaccine-primed LN in patients with advanced melanoma and renal cell cancer (RCC) for therapy.

MATERIALS AND METHODS

Irradiated autologous tumor cells admixed with bacille Calmette-Guérin (BCG) were used to vaccinate patients. Seven days later, draining LN were removed for activation with anti-CD3 monoclonal antibody (mAb) followed by expansion in interleukin-2 (IL-2). Activated LN cells were administered intravenously (IV) with the concomitant administration of IL-2.

RESULTS

A total of 23 patients were evaluated (11 melanoma and 12 RCC). Vaccine-primed LN were expanded ex vivo with a mean of 8.4 x 10(10) cells administered per patient. Among 20 patients assessed, 15 demonstrated minimal cytotoxicity of autologous tumor cells by the activated LN cells, with the remaining mediating nonspecific cytotoxicity. By contrast, a majority of the activated LN cells showed highly specific release of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon gamma (IFN-gamma) to autologous but not allogeneic tumor stimulation. This tumor-specific cytokine release was found to be major histocompatibility complex (MHC) class I-restricted, which indicates the involvement of CD8+ cells. Among 11 melanoma patients, one had a partial tumor response. Among 12 RCC patients, two had complete and two partial responses. A trend (P = .066) between the enhancement of delayed-type hypersensitivity (DTH) reactivity to autologous tumor after therapy and tumor regression was observed.

CONCLUSION

Tumor vaccines can be used to induce immunologically specific T-cell responses against melanoma and RCC in draining LN. Anti-CD3/IL-2 activation of primed LN cells can be reliably performed for clinical therapy and appears to have activity in patients with metastatic RCC.

Effect of bromodeoxyuridine on radiation-induced DNA damage and repair based on DNA fragment size using pulsed-field gel electrophoresis

We have used biphasic linear ramping pulsed-field gel electrophoresis (PFGE) to understand the effect of incorporation of bromodeoxyuridine (BrdUrd) on radiation-induced DNA damage and repair. This technique permits a determination of the fragment size distribution produced immediately after irradiation as well as during the repair period. We found that incorporation of BrdUrd increased the induction and decreased the repair of radiation damage. The fragment size distribution was consistent with a random breakage model. When we found that significantly more damage was detected after irradiation of deproteinized DNA compared to intact cells, we studied the effects of BrdUrd incorporation on the radiation response of cells or DNA at various phases of preparation for electrophoresis: cells adherent to the culture dish (A), trypsinized cells (B), agarose-embedded cells (C) and deproteinized DNA (D). Although there was a general tendency to detect more damage when irradiation was performed later in the preparation process, steps B and C were the only successive steps which were significantly different. These findings demonstrate that incorporation of BrdUrd randomly increases the induction of radiation damage and decreases its repair at the level of 200 kbp to 5 Mbp fragments. Furthermore, they confirm that the amount of damage detected depends upon the conditions of the cells or DNA at the time of irradiation.

A double-blind, randomized, placebo-controlled trial of prostaglandin E1 in liver transplantation

A double-blind placebo-controlled trial of intravenous prostaglandin PGE1 (40 micrograms/h) was conducted in adult orthotopic liver transplant recipients. Infusion was started intraoperatively and continued for up to 21 days. Patients were followed up for 180 days postoperatively. Among 172 patients eligible for treatment in the study, 160 could be evaluated (78 PGE1; 82 placebo). Patient and graft survival were similar (PGE1: 16 deaths, 9 retransplantations [7 survivors]; controls: 15 deaths, 6 retransplantations [3 survivors]). In patients with surviving grafts, however, PGE1 administration resulted in a 23% shorter mean duration of hospitalization following transplantation (PGE1: 24.4 days; controls: 31.8 days; P = .02) and a 40% shorter length of time postoperatively in the intensive care unit (PGE1: 8.2 days; controls 13.7 days; P = .05). Reduced needs for renal support (P = .03) or surgical intervention other than retransplantation (P = .02) were also noted with PGE1 use. Further, PGE1 administration resulted in a trend toward improved survival rates in patients with mild renal impairment (preoperative serum creatinine 1.5 mg percent or greater; P = .08). Neither the incidence of acute cellular rejection nor of primary nonfunction was significantly different in the two groups. Phlebitis was the only complication that was more common during PGE1 administration, (PGE1: 9; controls: 4). These results suggest that PGE1 use in hepatic allograft recipients reduces morbidity and may result in sizable cost reductions.

Use of fluorescence in situ hybridization (FISH) to study chromosomal damage induced by radiation and bromodeoxyuridine in human colon cancer cells

PURPOSE

Although the thymidine analog radiation sensitizer bromodeoxyuridine (BrdUrd) increases radiation-induced chromosomal aberrations, it is not known whether these aberrations are uniformly distributed among chromosomes. Using fluorescence in situ hybridization, we carried out a study to test the hypothesis that BrdUrd-induced radiosensitization may be mediated by nonuniform chromosomal damage.

METHODS AND MATERIALS

Log phase HT29 human colon cancer cells were exposed to 10 microM BrdUrd (or media alone) for one cell cycle, and the G1 cells were separated by centrifugal elutriation. Half of the control and BrdUrd samples were irradiated with 8 Gy. Cells were then incubated for 24-28 h, and metaphase spreads were prepared. Fluorescence in situ hybridization was performed using paint probes for chromosomes 1 and 4.

RESULTS

We found that radiation induced 0.20 aberrations per chromosome in chromosome 4. Based on the ratio of the relative lengths of chromosome 1-4 (1.34), it was predicted that chromosome 1 would have approximately 0.26 aberrations per chromosome. However, we observed 0.39 aberrations per chromosome 1, which was significantly greater than the predicted (p < 0.001 by chi-square). Incubation with BrdUrd prior to irradiation significantly increased the aberrations found in chromosome 1 (by a factor of 1.4) and chromosome 4 (by a factor of 1.9) compared to radiation alone (p < 0.001) for both chromosome 1 and 4).

CONCLUSION

This study demonstrates that individual chromosomes in human colon cancer cells show significantly different rates of aberration after irradiation. Furthermore, the BrdUrd-mediated increase in radiation-induced chromosomal aberrations may not be uniform among chromosomes.

P450 3A activity and cyclosporine dosing in kidney and heart transplant recipients

Interpatient differences in the kinetics of cyclosporine appear to result in part from interindividual differences in the catalytic activity of an enzyme termed P450 3A. We investigated the relationship between P450 3A activity, as measured by the erythromycin breath test (ERMBT), and the appropriate stable daily dose of cyclosporine as currently determined by physicians at our institution. The ERMBT was administered to kidney and heart allograft recipients who had attended at least two monthly clinic visits without having their daily cyclosporine dose changed. There was a significant positive correlation between the ERMBT result and the daily cyclosporine doses (in milligrams per kilogram) in both the heart (r = 0.68; p = 0.04; n = 9) and kidney (r = 0.68; p = 0.03; n = 10) recipients. To confirm our findings, we prospectively administered the ERMBT on multiple occasions to 20 patients who were undergoing kidney transplantation. Although the transplant physicians were blinded to the ERMBT results, the test predicted the stable daily doses of cyclosporine that they ultimately prescribed to the patients (r = 0.54; p = 0.015). When data from all 39 patients were pooled and subjected to multiple regression analysis, the ERMBT was the only variable examined that significantly correlated with the stable daily cyclosporine dose (r = 0.63; p < 0.001; n = 39). In the 20 patients prospectively studied, the prescribed daily dose of cyclosporine generally decreased during the months after surgery and the percentage changes in cyclosporine daily dose correlated with changes in P450 3A activity during this period (r = 0.47; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of aperiodic seasonality in non-Gaussian time series

Time series that arise from biological experimentation can exhibit seasonality where the lengths of the seasons may vary. In addition, such time series may not be stationary with respect to either mean, variance, or autocorrelation, thus making the usual waveform-fitting techniques inappropriate. An agglomerative clustering algorithm for identifying seasons in such series is proposed, consisting of an initialization step, iterative steps where clusters are combined into larger clusters, and a stopping rule for the iteration. The clusters can be associated with seasons or phases, and biological cycles can be identified from the phases. Results of a simulation and an analysis of luteinizing hormone concentrations are presented.

Predictors of toxicity in treating patients with neuroblastoma by radiolabeled metaiodobenzylguanidine

We searched for methods that would enable prescriptions of the maximum tolerable doses of iodine-131 metaiodobenzylguanidine (MIBG) and iodine-125 MIBG in the treatment of patients with neuroblastoma. We correlated doses, defined in different ways, with subsequent platelet levels in treated patients to determine accurate predictors of the most frequent toxicity, thrombocytopenia. Nine patients with neuroblastoma were given 131I-MIBG (4.9-8.1 GBq or 132-220 mCi) and ten were given 125I-MIBG (8.3-30.0 GBq or 224-809 mCi) as initial treatments. These therapies were sufficiently varied that correlations could be made between indices of the doses and the subsequent toxicity as reflected in circulating platelet levels. Predictors of toxicity were: whole-body absorbed dose of radiation (cGy) calculated from pretherapy tracer doses of 131I-MIBG; GBq/kg of body weight; and GBq/m2 of body surface area. Toxicity was recorded as the nadir of the platelet level and platelet/pretherapeutic level (platelet ratio). For treatments with 131I-MIBG, the highest correlation was obtained between cGy and the log10-transformed platelet ratio (r = -0.86), but comparison of GBq/m2 and the platelet nadir (r = -0.76) or the platelet ratio (r = -0.74) or the log10 transformed platelet ratio (r = -0.73) gave comparable and statistically significant results. For treatments with 125I-MIBG, significant correlations were obtained between GBq/m2 and the platelet ratio (r = -0.81) or GBq/kg and the log10-transformed platelet ratio; the correlation between cGy and any toxicity index was low. Per administered GBq, 131I-MIBG was 2.6 times more potent than 125I-MIBG in causing a platelet ratio of 0.1.(ABSTRACT TRUNCATED AT 250 WORDS)

An algorithm for robust non-linear analysis of radioimmunoassays and other bioassays

The four-parameter logistic function is an appropriate model for many types of bioassays that have continuous response variables, such as radioimmunoassays. By modelling the variance of replicates in an assay, one can modify the usual parameter estimation techniques (for example, Gauss-Newton or Marquardt-Levenberg) to produce parameter estimates for the standard curve that are robust against outlying observations. This article describes the computation of robust (M-) estimates for the parameters of the four-parameter logistic function. It describes techniques for modelling the variance structure of the replicates, modifications to the usual iterative algorithms for parameter estimation in non-linear models, and a formula for inverse confidence intervals. To demonstrate the algorithm, the article presents examples where the robustly estimated four-parameter logistic model is compared with the logit-log and four-parameter logistic models with least-squares estimates.

The use of biphasic linear ramped pulsed field gel electrophoresis to quantify DNA damage based on fragment size distribution

PURPOSE

The development of biphasic linear pulse ramping gel electrophoresis has permitted resolution of DNA fragments from 200 Kbp to 6 Mbp in a single gel. We used this technique to measure radiation-induced DNA damage based on fragment size.

METHODS AND MATERIALS

Human colon cancer cells (HT29 and LS174T) and Chinese hamster ovary cells were embedded in agarose, deproteinized, irradiated with 5-80 Gy, and assessed for DNA double strand breakage using pulsed field gel electrophoresis. The frequency of DNA double strand breakage determined using a previously published method was compared to the breakage frequency calculated using the fragment size distribution.

RESULTS

Both methods produced similar estimates for breakage frequency of approximately 5 x 10(-9) breaks Gy-1 bp-1.

CONCLUSIONS

These findings suggest that biphasic linear pulse ramping gel electrophoresis can yield a quantitative estimate of DNA fragment distribution resulting from irradiation. The ability to quantify the distribution of DNA fragment sizes produced by irradiation should yield important information concerning the mechanisms of both DNA double strand break induction and repair.

Correlation of the local and systemic cytokine response with clinical outcome following thermal injury

Eighty-eight patients with acute thermal injury were evaluated. Forty-eight hours after injury, TNF, IL-6, and IL-8 were significantly present in the systemic circulation, lung, normal skin, and thermally injured skin. The presence of TNF, IL-6, and IL-8 proteins in the lung, normal skin, and thermally injured skin were associated with TNF, IL-6, and IL-8 mRNA upregulation. Logistic regression analysis controlling for the Abbreviated Burn Severity Index demonstrated that the presence of IL-8 in the lung was associated with early pulmonary physiologic dysfunction (p = 0.006) and nosocomial pulmonary infection (p = 0.040). We conclude that acute thermal injury initiates an early systemic, lung, and skin response involving TNF, IL-6, and IL-8. The TNF, IL-6, and IL-8 protein present in the lung and skin in response to acute thermal injury are generated locally and do not originate from the systemic cytokine pool. The lung cytokine response to acute thermal injury may initiate local organ failure.

Therapy with unlabeled and 131I-labeled pan-B-cell monoclonal antibodies in nude mice bearing Raji Burkitt's lymphoma xenografts

Clinical trials of radioimmunotherapy (RIT) of lymphoma have produced frequent tumor regressions and remissions, but it has been difficult to determine to what extent these tumor responses have been due to antibody-specific targeted radiation, nontargeted radiation, and/or cytotoxicity mediated by the carrier monoclonal antibody (MoAb). In this report, RIT was studied in athymic nude mice bearing s.c. Raji human Burkitt's lymphoma xenografts using two different pan-B-cell MoAbs, MB-1 (anti-CD37) and anti-B1 (anti-CD20), which differ in isotype (and thus the potential for interaction with host effector mechanisms) and isotype-matched control antibodies either in the unlabeled state or labeled with 131I. When a single i.p. injection of 300 microCi 131I-labeled MB-1 (IgG1) was compared to treatment with unlabeled MB-1 or 300 microCi 131I-labeled MYS control IgG1 MoAb, an antibody-specific targeted radiation effect of RIT was seen. 131I-labeled MB-1 produced a 44 +/- 19% (SEM) reduction in tumor size at 3 weeks posttreatment, while unlabeled MB-1 or 300 microCi 131I-labeled MYS control IgG1 antibody treatment resulted in continued tumor growth over this period of time. In vitro studies demonstrated that MB-1 was incapable of mediating antibody-dependent cellular cytotoxicity using Raji tumor cell targets and human peripheral blood mononuclear cells. Similar to the MB-1 studies, treatment with 300 microCi 131I-labeled anti-B1 produced a 64% reduction in mean tumor size, while 300 microCi of control antibody resulted in a 58% increase in tumor size over the same 3-week period. In contrast to MB-1, however, unlabeled anti-B1 (an IgG2a MoAb which in vitro studies showed to be capable of antibody-dependent cellular cytotoxicity) also had a substantial antitumor effect. Indeed, 300 microCi 131I-labeled anti-B1 and unlabeled anti-B1 treatment (using an equivalent amount of total protein in the treatment dose) produced a similar specific reduction in tumor size. Increasing the radionuclide dose of anti-B1 to 450 microCi in another experiment did not produce a significant difference in tumor regression compared to a 300-microCi dose. These results suggest that the antitumor effects of 131I-labeled anti-B1 treatment were dominated by antibody-mediated cytotoxicity mechanisms, such that an antibody-specific targeted radiation effect could not be distinguished. In contrast, antibody-specific targeting of radiation was the dominant mechanism of tumor killing with 131I-labeled MB-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Imaging, dosimetry, and radioimmunotherapy with iodine 131-labeled anti-CD37 antibody in B-cell lymphoma

PURPOSE

This study was undertaken to evaluate the tumor targeting, toxicity, and therapeutic potential of the anti-B-cell-reactive monoclonal antibody MB-1 (anti-CD37) labeled with iodine 131 given in a nonmarrow ablative dose range in B-cell lymphoma patients who relapsed after chemotherapy.

PATIENTS AND METHODS

Twelve patients with MB-1-reactive tumors were infused first with 40 mg of trace-labeled (3 to 7 mCi) MB-1. Ten patients who had no serious toxicity postinfusion and who had successful tumor imaging on serial gamma scans then received at least one 40-mg radioimmunotherapy (RIT) dose (25 to 161 mCi). Tracer estimates of delivered whole-body dose (WBD) were used in prescribing a millicurie RIT dose for seven patients.

RESULTS

Eleven patients had positive tumor imaging after a tracer dose, including patients with bulky tumors and/or large tumor burdens (> or = 1 kg) +/- splenomegaly. However, overall sensitivity for the detection of known tumor sites was only 39%. In six of eight patients with dose-assessable tumors, the radiation dose to at least one tumor was 1.1 to 3.1 times higher than to any normal organ, excluding the spleen for a 40-mg tracer dose. Tracer-dose toxicities included reversible glossal edema in one patient, grade 3 hepatic transaminasemia in another, and early drops in both circulating B and T cells (with decreases in B cells more pronounced) in nearly all patients. RIT toxicity was primarily myelosuppression (especially thrombocytopenia), which had a delayed onset and protracted recovery (without significant recovery until at least 2 months post-RIT). Grade 3 myelosuppression in two of two patients who were treated at a tracer-projected 50-cGy WBD level (133 and 149 mCi) precluded further planned RIT dose escalation. Less myelosuppression was generally observed in patients who were treated at < or = 40-cGy WBD levels. Antimouse antibodies developed in two patients. Six patients had tumor responses post-RIT. Four had responses that lasted more than 1 month (2 to 6 months), which included one complete response, one partial response, one minor response, and one mixed response. Responses seemed to occur more frequently in imaged tumors than in nonimaged tumors. The most durable response occurred in a patient who had the best antibody targeting to tumor.

CONCLUSIONS

Although 131I-MB-1 has limited diagnostic value, it can produce tumor responses at nonmarrow ablative RIT doses. Further studies that focus on improving tumor targeting with this or other B-cell-reactive radiolabeled antibodies and on ameliorating the myelosuppression associated with the RIT-dosing approach used in this trial are warranted.

Erythromycin breath test predicts oral clearance of cyclosporine in kidney transplant recipients

It has been shown recently that cyclosporine is largely metabolized by P450IIIA (CYP3A), an enzyme whose catalytic activity varies significantly among patients. To determine whether heterogeneity in P450IIIA activity contributes to interpatient differences in cyclosporine dosing requirements, the oral pharmacokinetics of the drug were determined in 20 stable kidney transplant recipients. P450IIIA activity was then measured in each patient by use of the erythromycin breath test. In the 16 patients who were at steady state, the logarithm of the apparent oral clearance of cyclosporine correlated significantly with the rate of 14CO2 exhaled in breath after intravenous administration of [14C N-methyl]erythromycin (r = 0.55, p = 0.03). No significant correlations existed between apparent oral clearance and age, high-density lipoprotein cholesterol or low-density lipoprotein cholesterol, or hematocrit in these patients. We conclude that heterogeneity in P450IIIA activity significantly contributes to interpatient differences in dosing requirements of cyclosporine in kidney transplant patients.

Variations in patterns of DNA damage induced in human colorectal tumor cells by 5-fluorodeoxyuridine: implications for mechanisms of resistance and cytotoxicity

We have previously shown that treatment of the HT29 human colorectal tumor (HCT) cell line with 100 nM 5-fluorodeoxyuridine (FdUrd) induces DNA fragments ranging from 50 kilobases to 5 megabases. The studies reported here were conducted to characterize the kinetics, concentration dependence, and pharmacologic specificity of this process and to determine if such fragmentation varies among HCT cell lines. HT29 and SW620 cells yielded similar fragment size distributions upon treatment with either FdUrd or CB3717 [a folate analog inhibitor of thymidylate synthase (TS)]. With either of these agents the SW620 line required higher drug concentrations or longer incubation times than HT29 cells to achieve a given level of fragmentation or cytotoxicity, even though the two cell lines are equally sensitive to FdUrd-induced TS inhibition. These data indicate that SW620 resistance is not due to a lesion in the events leading up to TS inhibition but it may be due to a difference in the steps following TS inhibition. Aphidicolin, a DNA polymerase inhibitor, did not cause substantial fragmentation or cytotoxicity in these two cell lines, demonstrating that the fragmentation response to the other two drugs is not a general consequence of DNA synthesis inhibition. A third HCT line, HuTu80, gave rise only to a smaller and more discrete population of DNA fragments, ranging from approximately 50 to 200 kilobases, following exposure to FdUrd. Similar patterns were seen in this line upon treatment with CB3717 or aphidicolin, indicating that this fragmentation pattern is not specific to TS inhibition and may be characteristic of a more general response than that seen in the other two cell lines. DNA fragments induced by FdUrd in HuTu80 cells did not degrade into smaller pieces, demonstrating that the process by which they are formed is distinct from apoptosis. We conclude that the responses of HCT cells to FdUrd-induced TS inhibition vary significantly, that these differences may reflect heterogeneity in the mechanism of DNA damage formation, and that, in some cases, FdUrd resistance may be due to alterations in the fragmentation process.

The potential superiority of bromodeoxyuridine to iododeoxyuridine as a radiation sensitizer in the treatment of colorectal cancer

Although the thymidine analogues 5-bromo-2'-deoxyuridine (BrdUrd) and 5-iodo-2'-deoxyuridine (IdUrd) have been used successfully as radiation sensitizers in clinical trials, it is not clear which of these agents is the more promising to pursue. To begin to assess this question with regard to colorectal cancer metastatic to the liver, a study was carried out using HT29 human colon cancer cells in culture and implanted in nude mice as xenografts. Cells and animals were treated with BrdUrd +/- the thymidylate synthase inhibitor 5-fluoro-2'-deoxyuridine (FdUrd), and the results compared to our previous studies with IdUrd +/- FdUrd (T. S. Lawrence, M. A. Davis, P. E. McKeever, J. Maybaum, P. L. Stetson, D. P. Normolle, and W. D. Ensminger. Cancer Res., 51: 3900-3905, 1991). Using cultured cells, it was found that FdUrd (at concentrations of greater than 10 nM) increased: (a) the incorporation of BrdUrd into the DNA of cultured tumor cells; (b) BrdUrd-mediated radiosensitization; (c) BrdUrd-mediated increase in radiation-induced DNA damage; and (d) BrdUrd-mediated decrease in the repair of radiation-induced damage. The incorporation of BrdUrd was greater than or equal to the incorporation of IdUrd previously determined under the same exposure conditions. Studies using nude mice bearing HT29 xenografts showed that FdUrd increased BrdUrd incorporation more into tumors than into the normal liver. Most tumor cells incorporated BrdUrd (labeling index after a 4-day infusion = 87 +/- 2%; SE); in the liver, labeling was confined chiefly to nonparenchymal cells. In both the presence and absence of FdUrd, the incorporation of BrdUrd into tumors was significantly and consistently greater than the incorporation of IdUrd measured under the same conditions of drug administration (by a factor of 1.2-3.6). Furthermore, the administration of BrdUrd +/- FdUrd tended to produce less weight loss and hematological toxicity than IdUrd +/- FdUrd. These findings suggest that BrdUrd may be superior to IdUrd as a radiation sensitizer in the treatment of colorectal cancer metastatic to the liver.

Improved delivery of radiolabeled anti-B1 monoclonal antibody to Raji lymphoma xenografts by predosing with unlabeled anti-B1 monoclonal antibody

A human B-cell lymphoma xenograft model was used to test whether the administration of unlabeled MoAb prior to injection of radiolabeled monoclonal antibody (MoAb) improves delivery of the radiolabeled MoAb to tumor prior to testing in clinical radioimmunotherapy trials. The anti-B1/CD20 pan-B-cell MoAb reactive with human B-cell lymphomas and leukemias but not reactive with mouse B-cells was used in this study. Athymic nude mice bearing human Raji Burkitt lymphoma xenografts were given injections of 2.5 muCi (0.3 microgram) 131I-labeled anti-B1 with or without a 2-h prior single injection of 100 micrograms of unlabeled anti-B1 antibody. Four days later the animals given injections of 131I-labeled anti-B1 and the unlabeled anti-B1 predose had a tumor uptake of 12.72 +/- 1.17% (SEM) of injected dose/g which was 44% greater than the animals receiving the 131I-labeled anti-B1 alone (P = 0.014). The uptake in most normal tissues was unchanged, although the blood level of 131I-labeled anti-B1 appeared to be greater following unlabeled anti-B1 predosing (P = 0.067). Predosing with isotype matched irrelevant MoAb did not result in a greater tumor uptake or blood concentration of 131I-labeled anti-B1 compared to the administration of 131I-labeled anti-B1 alone. In studies using 111In-labeled anti-B1, the effect of unlabeled antibody predosing was more pronounced. For animals given injections of 4.5 muCi (0.4 microgram) 111In-labeled anti-B1 and the unlabeled anti-B1 predose, the uptake in tumor was 12.37 +/- 2.07% of injected dose/g which was 162% greater than the animals receiving the 111In-labeled anti-B1 alone (P = 0.009). Predosing decreased 111In-labeled anti-B1 uptake in spleen, while the blood level was significantly greater. Predosing was more effective than simultaneous injection in improving tumor delivery. When tumor-bearing mice were either simultaneously given injections of 36 micrograms of unlabeled anti-B1 and 4 micrograms 111In-labeled anti-B1 or were given preinjections of 36 micrograms unlabeled anti-B1 3 h prior to injection of 4 micrograms 111In-labeled anti-B1, tumor uptake 3 days later was 1.3-fold higher in the animals which received the preinjection of unlabeled antibody (P = 0.011). As the quantity of unlabeled anti-B1 was increased (36, 96, 996 micrograms) in the predose, significantly greater uptake in tumor was observed, although this uptake appeared to plateau at the highest predoses.(ABSTRACT TRUNCATED AT 400 WORDS)

Biochemical modulation of 5-bromo-2'-deoxyuridine and 5-iodo-2'-deoxyuridine incorporation into DNA in VX2 tumor-bearing rabbits

The thymidine analogues 5-bromo-2'-deoxyuridine (Brd-Urd) and 5-iodo-2'-deoxyuridine (IdUrd) compete with thymidine for incorporation into the DNA of replicating cells. This incorporation results in radiosensitizing effects which are directly related to the degree of analogue substitution. In vitro and in vivo evidence suggests that preadministration or coadministration of the thymidylate synthetase inhibitors fluorouracil and 5-fluoro-2'-deoxyuridine (FdUrd) can modulate analogue incorporation into DNA. We have evaluated in the rabbit VX2 tumor model the effects of thymidylate synthetase inhibitor (fluorouracil or FdUrd) coadministration (as 24-hour, intravenous infusions) on the incorporation of BrdUrd or IdUrd into the DNA of relevant normal tissues (bone marrow, gut mucosa) and intrahepatic VX2 tumor. Tissues were harvested and processed for gas chromatography-mass spectrometry analysis of the thymine, 5-bromouracil, and 5-iodouracil contents in hydrolyzed DNA. Coadministration of FdUrd resulted in statistically significant (P less than .01) enhancement of IdUrd incorporation into the DNA of intrahepatic VX2 tumor and normal (bone marrow and duodenal mucosa) rabbit tissues. Coadministered fluorouracil, on the other hand, significantly enhanced IdUrd incorporation only into DNA of intrahepatic VX2 tumor. Statistically significant enhancement of BrdUrd incorporation was achieved only with FdUrd coadministration and then only into the DNA of intrahepatic VX2 tumor. The percent of thymine replaced by analogue (I) is related to the steady-state arterial plasma drug concentration (C) by the Michaelis-Menten equation: I = I(MAX.) C/(C50 + C). The primary effect of FdUrd coadministration on BrdUrd incorporation into VX2 tumor DNA was a reduction of the C50 parameter (plasma BrdUrd concentration eliciting I = I(MAX)/2) from 8.17 microM to 1.78 microM. On the other hand, the I(MAX) parameter (I as C approaches infinity) was only slightly affected (29.7% to 25.2%). Thus, the degree to which the modulator enhanced analogue incorporation varied inversely with the analogue's steady-state plasma concentration. These results, which describe potential tissue specificity of modulator efficacy and characterize the effects of thymidylate synthetase inhibitor modulation on thymidine analogue incorporation pharmacodynamics, should provide guidance as to dose scheduling of BrdUrd and IdUrd in clinical trials for improved tumor specificity of uptake.

Long-term results of [131I]metaiodobenzylguanidine treatment of refractory advanced neuroblastoma

Fourteen patients with advanced neuroblastoma, which was unresponsive to or had relapsed despite conventional therapy, were entered into a phase I/II trial of [131I]metaiodobenzylguanidine (131I-MIBG). Doses ranged from 1.85-8.14 GBq each (50-220 mCi), with cumulative doses of 1.85-24.20 GBq (50-654 mCi) in one to three doses. Side effects included mild nausea and vomiting and moderate myelosuppression which occurred in nine patients. Subjective responses occurred in five patients. Four patients had objective responses (one partial, two minor and one mixed). Two of these patients remain alive 80 and 60 months after beginning 131I-MIBG therapy. Comparison of the 131I-MIBG treated patients with 11 carefully matched control patients treated with an advanced current chemotherapy protocol (CCG 8605) was performed by means of Kaplan-Meier life table analysis. The 14% four-year survival with 131I-MIBG compared favorably with the 6% achieved by salvage chemotherapy. We thus believe 131I-MIBG may have a role in the management of neuroblastoma.

Fluorodeoxyuridine-mediated modulation of iododeoxyuridine incorporation and radiosensitization in human colon cancer cells in vitro and in vivo

A study was conducted to assess the potential of 5-fluoro-2'-deoxyuridine (FdUrd) to increase the incorporation and radiosensitizing properties of 5-iodo-2'-deoxyuridine (IdUrd) using HT29 human colon cancer cells both in vitro and in nude mice bearing these tumors as xenografts. The purpose of this study was to assess (a) whether FdUrd could increase IdUrd efficacy using clinically achievable concentrations of drugs; (b) the relationships among radiosensitization, DNA damage and repair, and analogue incorporation; and (c) whether FdUrd improved the selectivity of IdUrd incorporation into tumor cells compared to normal tissues. It was found that FdUrd, at clinically achievable concentrations (1-100 nM), significantly increased IdUrd incorporation under all conditions but particularly when the IdUrd concentration was less than or equal to 10 microM. FdUrd increased IdUrd-mediated radiosensitization in proportion to the increase in IdUrd incorporation. FdUrd potentiated the ability of IdUrd to increase radiation-induced DNA double-strand breaks and to slow their repair. When IdUrd alone (100 and 200 mg/kg/day) was infused into nude mice bearing tumors, the extent of thymidine replaced in the tumor was 1.6 +/- 0.4 (mean +/- SE) and 2.5 +/- 0.4%, respectively. The combination of FdUrd (0.1 mg/kg/day) and IdUrd (100 mg/kg/day) increased the incorporation in the tumor to 5.3 +/- 0.9% with less toxicity than resulted from the use of 200 mg/kg/day of IdUrd alone. These data show that FdUrd is an effective biomodulator, because, for the same extent of normal tissue incorporation, the combination of IdUrd and FdUrd produces significantly greater incorporation into the tumor compared to the use of IdUrd alone. Furthermore, they suggest that the regional application of FdUrd with IdUrd, either through the use of regional infusions or in combination with focused irradiation, could potentially improve the outcome of treatment of localized gastrointestinal cancer.

Urodynamic tests for female geriatric urinary incontinence

Most urodynamic tests currently in use in the evaluation of female urinary incontinence have not been applied to a community-based sample to determine their specificity. In this study of a random sample of noninstitutionalized elderly, 258 self-reported continent and 198 self-reported incontinent women sixty years and older, who participated in a household survey, underwent a clinic evaluation (history, physical examination, and urinalysis); of these 67 continent and 100 incontinent female respondents underwent urodynamic testing. The uroflowmetry, cystometry, and supine static urethral pressure profilometry (UPP) findings did not differ significantly between continent and incontinent subjects (whether based on a self-report or a clinician's diagnosis of urinary continence status). Standing static and dynamic UPP and lateral cystography showed significant differences between self-reported continent and incontinent respondents. The provocative stress test significantly distinguishes continence from incontinence, and stress incontinence from other types. The sensitivity of the provocative stress test was 39.5 percent, whereas its specificity is 98.5 percent. Urodynamic testing including uroflow study, static UPP, and lateral cystography should not be used as a screening test but rather selectively as a confirmatory test, and to determine the therapeutic approach, and to assess the outcome of therapy.

Two-year incidence, remission, and change patterns of urinary incontinence in noninstitutionalized older adults

In this study, patterns of urinary incontinence, its severity and types were studied by three sequential data collections at annual intervals. The data are from a panel survey of a probability sample of 1,956 noninstitutionalized persons aged 60 and over residing in Washtenaw County, Michigan, who were interviewed in their homes about urine loss. Based on these self-reports, the prevalence of urinary incontinence was 18.9% in men and 37.7% in women. One-year incidence rates of about 20% among women and about 10% among men were found. One-year remission rates were about 12% for women and about 30% for men. When becoming incontinent, respondents were most likely to develop mild incontinence. Those who changed their severity level were most likely to progress from mild to moderate.

Small-area variation in hospital discharge rates. Do socioeconomic variables matter?

Although numerous studies have been made of the determinants of small-area variation in hospital discharge rates, there is still disagreement about the role of socioeconomic factors. The lack of consensus stems, in part, from the difficulty in comparing results across studies that use different units and methods of analysis. Many of the studies using well-defined hospital service areas did not have the data needed to conduct a controlled analysis of the determinants of hospital utilization. Most of the studies that have performed controlled analyses have relied on larger geopolitical areas, which are not believed to capture self-contained health care systems. The study described here used a consistent set of data, three methods of analysis, and two units of analysis to test the importance of socioeconomic characteristics in explaining the variation in medical and surgical discharge rates in Michigan. Socioeconomic factors are found to be statistically significant determinants of the variation in both medical and surgical discharge rates, whether the method of analysis is simple correlations or multiple regressions, and whether the unit of analysis is the county or a well-designed hospital service area. These results suggest that previous small-area variation studies may have incorrectly concluded that socioeconomic characteristics do not explain differences in utilization rates.

Prevalence and outcome of surgery for female incontinence

A 4.7 percent surgery rate to correct urine loss conditions was found by a large scale survey of sixty-year and older non-institutionalized women in a Michigan county. The initial postoperative results reported by the respondents were 74 percent complete continence and 23 percent partial relief. The long-term self-reported outcomes (two years or more post-surgery) were an absolute continence rate of 39 percent and 17 percent with mild incontinence (the median time since surgery was 12 years), whereas the short term (4-23 months, mean 7.1 months) absolute continence rate was 71 percent. The characteristics of the incontinence respondent who had previous surgery showed 70 percent having mixed stress-urge type of incontinence and 66 percent losing urine almost weekly or daily. Bladder emptying symptoms were reported by 30.4 percent of the continent previously-operated respondents compared with 13.0 percent of the incontinent previously-operated respondents. All continent respondents and 84 percent of the incontinent respondents believed that physicians can help people with a urine loss condition.

Methods used to manage urinary incontinence by older adults in the community

This paper addresses the ways that noninstitutionalized older adults deal with involuntary urine loss. The data come from a 1983-1984 sample survey of Washtenaw County, Michigan residents aged 60 and over. Five hundred twelve self-reported incontinent respondents are included in the analyses. About a quarter of the incontinent respondents had discussed their condition with a doctor in the previous year, while 66% used one or more methods to control urine loss. Respondents preferred using absorbent products (47% of those who used some method) and locating a toilet upon reaching a destination (42%). Fewer respondents manipulated their voiding patterns (29%) or diet and fluid intake (17%), or did pelvic muscle exercises (10%). Only 7% were taking medication for their incontinence. Logistic regression analyses were performed to identify factors associated with the choice of actions. Predictors were taken from theoretical models of health service utilization and health behavior, and included predisposing characteristics, health beliefs, enabling factors, and illness variables. Illness variables, particularly severity and type of incontinence, were the best predictors of consultation with a doctor and use of any urine control method. The predictors were less useful for understanding the choice of a specific method.

Clinical and cystometric characteristics of continent and incontinent noninstitutionalized elderly

A survey of the clinical and cystometric characteristics of continent and incontinent elderly subjects living in a community has not been reported previously. Household respondents identified initially from a random probability sample were invited to undergo a free clinic evaluation followed by an invitation to free urodynamic testing. Of the 1,955 household respondents 456 women and 298 men attended the clinic. From this group 169 women and 94 men accepted the urodynamic invitation. Cystometric studies reveal a significant difference between the over-all prevalence of uninhibited detrusor contraction between genders, 7.9 per cent for women and 35 per cent for men. The occurrence of uninhibited detrusor contractions is more prevalent among incontinent than continent subjects and this difference is marginally significant. There is no significant association between uninhibited detrusor contractions and symptoms of difficult bladder emptying, irritative symptoms, voiding frequency, nocturia and urodynamic diagnosis of outlet obstruction (normal or high pressure and poor flow) but there were significant associations with responses to questions about the delay in getting to a toilet. The mean bladder capacities of men and women do not differ significantly between the different age groups but the capacity is significantly smaller for those with uninhibited detrusor contractions. The post-void residual urine volume shows no association with the continence status. These findings raise questions regarding our conventional thinking as to the etiology of uninhibited detrusor contractions, especially in men, and of urinary incontinence in general.