Harmonization of United States, European Union and Canadian First-in-Human Regulatory Requirements for Radiopharmaceuticals-Is This Possible?

In recent years, several new radiotracers and radionuclide therapies have been developed. There is a renaissance in nuclear medicine and molecular imaging today, for example, in terms of the ability to image and treat neuroendocrine and prostate malignancies. In order to be able to bring a new drug product from bench to bedside and assist patients, while also ensuring patient safety, stringent regulations must be met. However, differences in regulatory requirements, often based on jurisdictional politics rather than scientific evidence, can hinder global co-operation, increase expense, and slow progress. In an effort to rise above these differences, nuclear medicine advocacy organizations, regulators, and international agencies have begun to identify commonalities in the regulations to achieve harmonization. Indeed, a more streamlined approach to radiopharmaceutical drug development across jurisdictions could be achieved through establishing harmonized requirements for pre-clinical studies and manufacturing standards. This paper provides an educational overview of the regulatory and submission requirements governing investigational radiopharmaceuticals for first-in-human radiopharmaceuticals across the European and North American continents. It is hoped that through ongoing collaboration, regulatory reform and harmonization can become a reality and speed access to the most up-to-date evidence-based patient care for all.

ASSESSMENT OF EFFECTIVE DOSE FROM CONE BEAM CT IMAGING IN SPECT/CT EXAMINATION IN COMPARISON WITH OTHER MODALITIES

The aim of this study was to assess radiation dose from the cone beam computed tomography (CBCT) component of single photon emission tomography/computed tomography (SPECT/CT) examinations and to compare it with the radiopharmaceutical related dose as well as dose from multidetector computed tomography (MDCT). Effective dose (ED) from computed tomography (CT) was estimated using dose-length product values and anatomy-specific conversion factors. The contribution from the SPECT component was evaluated using ED per unit administered activity for the radiopharmaceuticals listed in the International Commission on Radiological Protection Publications 80 and 106. With the exception of cardiac studies (0.11 mSv), the CBCT dose (3.96-6.04 mSv) was similar to that from the radiopharmaceutical accounting for 29-56 % of the total ED from the examination. In comparison with MDCT examinations, the CBCT dose was 48 and 42 % lower for abdomen/pelvis and chest/abdomen/pelvis scans, respectively, while in the chest the CBCT scan resulted in higher dose (23 %). Radiation dose from the CT component should be taken into consideration when evaluating total SPECT/CT patient dose.

Microsatellite markers in the western prairie fringed orchid, Platanthera praeclara (Orchidaceae)

PREMISE OF THE STUDY

Primers for 31 microsatellite-containing loci were developed for the threatened orchid Platanthera praeclara to enable characterization of the population genetics of this tallgrass prairie native. •

METHODS AND RESULTS

Sixteen polymorphic microsatellite loci were identified from four populations. Six of these loci were not in linkage disequilibrium. The average number of alleles per locus per population ranged from 6.4 to 8.9. •

CONCLUSIONS

The results indicate that six of the polymorphic loci will be useful in future studies of population structure, gene flow, and genetic diversity.

P2-14-06: Clinical and Pathologic Characteristics of Haitian Breast Cancer Patients in a Tertiary Care Safety Net Hospital

Background: There is limited literature regarding Haitian women and breast cancer. What exists is based on screening with no literature on clinical or pathologic subtypes of breast cancer. We examined patient and tumor characteristics in Haitian born women with invasive breast cancer in our ethnically diverse tertiary care hospital.

Methods: We expanded a pre-existing database to include all women diagnosed with breast cancer from 1998–2011. From the electronic medical record we documented age, body mass index (BMI), place of birth, self-identified race/ethnicity, date of diagnosis, T, N, M stage, grade, ER, PR, HER2 expression, recurrence and treatment data including neoadjuvant, surgical, adjuvant and radiation therapy and adequacy of treatment. We determined associations using contingency tables and multivariate logistic regression.

Results: 480 cases identified. Patients were racially diverse: 35% white (W), 41% black (B), 14% Hispanic and 10% other with 8% of patients self-identified as Haitian (Ha). Ha patients were younger at diagnosis, with mean age 55.1 vs. 59.4 overall p=0.04. Mean age W: 62 B: 58. Mean BMI was not significant. Ha women had an odds ratio (OR) of triple negative (Tneg) breast cancer: 3.078 (CI: 1.608−5.892, p=0.0007), B: 3.392 (CI: 2.113 - 5.441, p=<0.0001), W: 0.339 (CI: 0.192−0.599, p=0.0002) when controlling for age and BMI. Ha OR of ER+: 0.459 (CI: 0.246−0.859, p=0.0149), B: 0.384 (CI: 0.257 - 0.575, p<0.0001), W: 0.8771 (CI: 1.525 - 3.792 p=0.0002). Ha OR of PR+: 0.535 (CI: 0.288−0.995, p=0.0481) when controlling for age and BMI. Her2+ expression was not significantly different. OR of recurrence in Ha: 2.110 (CI: 1.068−4.171, p= 0.0317) controlling for age and BMI. When grade was added to the multiple regression model, the odds of recurrence in Ha women was no longer significant OR 1.845 (CI: 0.923−3.690, p=0.0833); however, recurrence appeared to be associated with grade OR 1.858 (CI: 1.273−2.711, p=0.0013). Higher grade was significantly associated with Ha status, controlling for categorical age and BMI (mean score differences p = 0.0086). Crude rates of each grade in Ha women were 4% grade 1, 38% grade 2, 58% grade 3 and the rates in non-Ha women were 14% grade 1, 48% grade 2, 38% grade 3. Exploring recurrence further, treatment records were reviewed and while a minority of patients did not receive adequate primary therapy, the majority of women did receive adequate therapy.

Conclusions: Ha women were younger at diagnosis, had a higher risk of triple negative, ER negative and PR negative tumors and had more grade 3 tumors when controlling for age and BMI. Rates of recurrence appeared higher in Ha women, but the association was no longer significant when controlling for grade in addition to age and BMI. Analysis is ongoing, and we expect to report data on survival and treatment adequacy when compared to other groups in our dataset.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-14-06.

P1-08-24: Clinical and Pathologic Characteristics of Diabetic Breast Cancer Patients in a Tertiary Care Safety Net Hospital

Background: Recent studies have indicated an increased risk of breast cancer in women with diabetes, and an increase in disease specific mortality in patients with diabetes and breast cancer. Clinical and pathologic features of diabetic women with breast cancer have not been described. We examine tumor characteristics in diabetic women in our ethnically diverse tertiary care hospital that may help explain the increased mortality seen in diabetic women diagnosed with breast cancer.

Methods: We expanded a pre-existing database to include all women diagnosed with breast cancer from 1998–2011. From the electronic medical record we documented age, body mass index (BMI), place of birth, self-identified race/ethnicity, date of diagnosis, T, N, M stage, grade, ER, PR, HER2 expression, presence of diabetes (DM) or thyroid disease at diagnosis, recurrence and treatment data including neoadjuvant, surgical, adjuvant and radiation therapy and adequacy of treatment. We determined associations using contingency tables and multivariate logistic regression.

Results: 480 cases were identified. Patients were racially diverse: 35% white [W], 41% black [B], 14% Hispanic and 10% other. 23% had DM, 47% were obese (body mass index [BMI] >30). Age in DM vs. non-DM were 63.327 vs. 57.729 (p= < 0.0001) and BMI in DM vs. non-DM were 32.749 vs. 29.433 (p<0.001). When exploring odds ratios (OR) of different tumor subtypes, none were statistically significant when controlling for age and BMI. The OR calculated were as follows: Triple negative 1.00 (confidence interval [CI]: 0.6−1.666, p = 0.9996), ER+ 1.063 (CI: 0.68−1.662, p=0.7877), PR+ 1.005 (CI: 0.67−1.506, p=0.9811), HER2+ 1.011 (CI: 0.578−1.768, p= 0.8535), recurrence: 1.090 (CI: 0.634−1.873, p= 0.7558). There were no significant interactions with DM and T, N stage when controlling for age and BMI. T stage: p=0.6962, N stage: p=0.7349 and recurrence p=0.5469 on recurrence controlling for age, BMI and grade: p=0.5462. There was no significant association between grade in DM vs. no DM with rates of grade in DM as follows: grade 1: 10.81%, grade 2: 49.55%, grade 3: 39.64% and in non-DM grade 1: 13.55%, grade 2: 45.8% and grade 3: 40.65%. Mean score difference p=0.7588. Conclusions: We did not find significant differences in our DM women compared with non-DM women when evaluating tumor subtype, T stage, N stage, grade or recurrence. In our patient population these factors do not play a role in the increased cause specific mortality in DM patients with breast cancer. Other factors must play a role in this and should be explored further.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-24.

The establishment of genetically engineered canola populations in the U.S

Concerns regarding the commercial release of genetically engineered (GE) crops include naturalization, introgression to sexually compatible relatives and the transfer of beneficial traits to native and weedy species through hybridization. To date there have been few documented reports of escape leading some researchers to question the environmental risks of biotech products. In this study we conducted a systematic roadside survey of canola (Brassica napus) populations growing outside of cultivation in North Dakota, USA, the dominant canola growing region in the U.S. We document the presence of two escaped, transgenic genotypes, as well as non-GE canola, and provide evidence of novel combinations of transgenic forms in the wild. Our results demonstrate that feral populations are large and widespread. Moreover, flowering times of escaped populations, as well as the fertile condition of the majority of collections suggest that these populations are established and persistent outside of cultivation.

Tandem high-dose therapy in rapid sequence for children with high-risk neuroblastoma

PURPOSE

Advances in chemotherapy and supportive care have slowly improved survival rates for patients with high-risk neuroblastoma. The focus of many of these chemotherapeutic advances has been dose intensification. In this phase II trial involving children with advanced neuroblastoma, we used a program of induction chemotherapy followed by tandem high-dose, myeloablative treatments (high-dose therapy) with stem-cell rescue (HDT/SCR) in rapid sequence.

PATIENTS AND METHODS

Patients underwent induction chemotherapy during which peripheral-blood stem and progenitor cells were collected and local control measures undertaken. Patients then received tandem courses of HDT/SCR, 4 to 6 weeks apart. Thirty-nine patients (age 1 to 12 years) were assessable, and 70 cycles of HDT/SCR were completed.

RESULTS

Pheresis was possible in the case of all patients, despite their young ages, with an average of 7.2 x 10(6) CD34(+) cells/kg available to support each cycle. Engraftment was rapid; median time to neutrophil engraftment was 11 days. Four patients who completed the first HDT course did not complete the second, and there were three deaths due to toxicity. With a median follow-up of 22 months (from diagnosis), 26 of 39 patients remained event-free. The 3-year event-free survival rate for these patients was 58%.

CONCLUSION

A tandem HDT/SCR regimen for high-risk neuroblastoma is a feasible treatment strategy for children and may improve disease-free survival.

Occult tumor contamination of hematopoietic stem-cell products does not affect clinical outcome of autologous transplantation in patients with metastatic breast cancer

PURPOSE

To determine whether occult tumor contamination of autologous bone marrow or peripheral-blood progenitor cells (PBPC) influences clinical outcome after high-dose chemotherapy in patients with stage IV breast cancer.

PATIENTS AND METHODS

We used an immunocytochemical assay capable of detecting one tumor cell in 5 x 10(5) hematopoietic cells to analyze bone marrow and/or PBPC collections obtained from 57 consecutive women with chemotherapy-sensitive metastatic breast cancer who received high-dose chemotherapy. The influence of occult tumor on time to progression, overall survival, and first site of recurrence (old or new) was studied.

RESULTS

Twenty-three of 57 (40%) patients received bone marrow (n=6) or peripheral-blood progenitor collections (n=17) that contained microscopic cancer. Median time to progression and overall survival were 9 and 22 months in patients who did not receive infused tumor cells, compared with 10 and 24 months, respectively, in those who received occult tumor (P=not significant [NS]). Worse survival, but not time to progression, was observed in six patients who received > or = 2/100,000 tumor cells. Regardless of whether occult tumor was infused, the majority of relapses occurred in prior, rather than new sites of disease. Three patients who received stem-cell products contaminated by microscopic breast cancer remain free from progression at 21+, 47+, and 52+ months.

CONCLUSION

Microscopic tumor was frequently detected by immunocytochemistry in hematopoietic stem-cell products, but did not predict for inferior treatment outcome in this cohort of patients with metastatic breast cancer. Quantitative information regarding infused tumor burden may have prognostic significance.

Minimal residual disease in solid tumor malignancies: a review

The increase in the number of patients treated with high-dose chemotherapy/autologous stem cell transplantation (HDC/ASCT) for solid tumor malignancies has generated concern about the infusion of tumor cell contamination in the graft. In an effort to study so-called minimal residual disease (MRD) in the HDC/ASCT setting, a variety of assay methods have been used. Although these assays vary in terms of sensitivity and specificity of tumor detection, they are in agreement as to the presence and viability of tumor cells in ASCT grafts. A growing body of evidence indicates that MRD is present in ASCT grafts from neuroblastoma, breast cancer, and ovarian cancer patients. More importantly, several retrospective studies have determined that the infusion of tumor cells with the ASCT graft is strongly associated with post-ASCT relapse. Gene-marking studies have directly demonstrated that infused tumor cells are present at sites of disease relapse. Thus, the issue of tumor contamination of autologous grafts is an area of growing concern. This review article details the current status of MRD in solid tumor malignancies, with emphasis on assay methodology, clinical utility, and clinical relevance in transplantation medicine.

Decrease in tumor cell contamination and progenitor cell yield in leukapheresis products after consecutive cycles of chemotherapy for breast cancer treatment

In this retrospective study, we assessed the impact of each of three consecutive cycles of conventional-dose chemotherapy on CD34+ cells, colony-forming units granulocyte-macrophage (CFU-GM), and contaminating breast cancer cells collected in the leukapheresis products of patients with metastatic breast cancer. The patients subsequently underwent high-dose chemotherapy followed by autologous blood progenitor cell transplantation. We analyzed 172 leukapheresis products from 17 patients and have correlated the long-term clinical outcome with tumor cell contamination. The induction chemotherapy regimen consisted of three cycles of cyclophosphamide 750 mg/m2 i.v., epirubicin 100 mg/m2, and 5-fluorouracil (5-FU) 750 mg/m2 i.v., followed by 5 microg/kg body weight of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) daily until leukapheresis was completed. An average of 10 leukapheresis products (three to four collections after each cycle of chemotherapy) were obtained from each patient. Numbers of CD34+ cells, CFU-GM, and mononuclear cells (MNCs) in the leukapheresis products were determined at the time of collection. Aliquots from the same products were frozen and breast cancer cells were detected by immunocytochemistry with a cocktail of anti-cytokeratin antibodies (AE-1, AE-3, CAM 5.2, Keratin 8+18+19) using a standardized immunoalkaline phosphatase method. A minimum of 10(6) cells were examined by light microscopy and by at least two blinded observers. Cells were considered positive when immunostaining was detected in the cytoplasm and on the cell membrane, and cellular morphology was consistent with a malignant phenotype. Of the 172 samples analyzed, 13 of 57 (23%) leukapheresis products collected after cycle I were positive for tumor cells; 3 of 60 (5%) after cycle II; and 4 of 55 (7%) after cycle III. The likelihood of contamination by breast cancer cells after cycle I was significantly higher than after subsequent cycles of chemotherapy (p = 0.0052). Simultaneously, there was a significant decrease in quantity of CD34+ cells and CFU-GM (p < 0.0001 for both comparisons). Our study indicated that leukapheresis products collected after the second or third cycles of induction chemotherapy carry a significantly lower likelihood of tumor cell contamination, albeit the quantity of CD34+ cells or CFU-GM collected was also significantly reduced.

Early tumor cell dissemination in patients with clinically localized carcinoma of the prostate

Because a significant number of patients with pathologically organ-confined carcinoma of the prostate subsequently develop recurrent disease, metastasis may occur much earlier than previously believed. We have used a reverse transcription-PCR assay for prostate-specific antigen mRNA and an immunocytochemical staining method for cytokeratins to test this hypothesis in paired peripheral blood (PB) and bone marrow (BM) specimens from 71 patients with clinically localized disease before radical prostatectomy, 14 patients with advanced-stage carcinoma of the prostate, and 30 controls (young healthy volunteers, patients without prostate disease, and patients with benign prostatic hyperplasia). Controls were negative in BM and PB. Fifty-six% of patients with organ-confined tumors (pT2) and 73% of those with extracapsular extension (pT3) were positive in the BM versus 16% of those with pT2 tumors and 27% of those with pT3 tumors in the PB. Patients with advanced-stage disease were positive in 86% of BM versus 71% of PB. The sensitivity of the immunocytochemistry assay to detect tumor cells was lower as compared with the reverse transcription-PCR assay. The results suggest that tumor cell dissemination occurs early during disease progression. Prostate cells seem to preferentially concentrate in the BM rather than the PB, which may be due to sequestration there by homing mechanisms. As the rate of detection in the BM exceeds the proportion of patients with subsequently progressing disease, we hypothesize that only a subset of these cells can survive in the BM and evolve to clinically apparent disease.

Tumor cell contamination of bone marrow harvest products: clinical consequences in a cohort of advanced-stage breast cancer patients undergoing high-dose chemotherapy

Patients undergoing high-dose chemotherapy (HDC) with autologous stem cell rescue (ASCR) may have tumor cells inadvertently infused if their stem cell product is tumor contaminated. We used an immunocytochemical (ICC) method to analyze 31 histologically negative bone marrow (BM) specimens taken from women with advanced-stage breast cancer at the time of BM harvest before HDC. All 31 patients were treated on one of three consecutive HDC protocols and received BM or BM and peripheral stem cells (PSC) as ASCR. Six of 26 evaluable patients had ICC-detectable contaminating tumor cells in their BM harvests. These 6 patients had a trend toward decreased overall survival compared with those patients without ICC-detectable tumor cells (17 months median versus 25+ months, p = 0.11, log rank test for those patients achieving complete response, CR, from HDC). The sites of relapse in the ICC-positive and ICC-negative groups were not notably different when analyzed for new sites versus previous sites of disease. Therefore, our retrospective analysis of a small cohort of patients suggests that the infusion of tumor cells in breast cancer patients undergoing HDC may confer a poor prognosis. Relapse patterns however suggest failure both in new sites and in sites of previous disease. Additional studies in expanded patient populations are needed to explore further the role of tumor cell infusion in ASCR and the possible clinical benefits of tumor cell removal procedures.

Similar breast cancer cell contamination of single-day peripheral-blood progenitor-cell collections obtained after priming with hematopoietic growth factor alone or after cyclophosphamide followed by growth factor

PURPOSE

To evaluate tumor-cell contamination of peripheral-blood progenitor-cell (PBPC) collections obtained after priming with granulocyte colony-stimulating factor (G-CSF).

PATIENTS AND METHODS

Immunocytochemical (ICC) and tumor clonogenic (TCA) assays were used to analyze tumor-cell contamination of pretreatment peripheral-blood (PB) and bone marrow (BM) samples, and of PBPC collection samples obtained after priming with G-CSF 5 micrograms/kg/d for 5 or 7 days in 38 women with advanced breast cancer undergoing high-dose chemotherapy (HDC). Results were compared with 37 historical control patients who underwent PBPC mobilization with cyclophosphamide (4 g/m2) followed by granulocyte-macrophage colony-stimulating factor (GM-CSF) 5 micrograms/kg/d for 14 days.

RESULTS

Before PBPC priming with G-CSF, only one of 37 (3%) PB and four of 36 (11%) BM samples had tumor cells detected by ICC. Tumor-cell contamination of PBPC collections obtained after 5 or 7 days of G-CSF priming was observed in only three of 38 patients (8%). All patients with tumor cells detected in the PBPC collection had stage IV disease. Cells with in vitro clonogenic potential were detected only in the pretreatment BM sample in one patient, and another two patients had ICC- and TCA-positive PBPC samples despite tumor-negative PB and BM before priming. These results are similar to those previously reported for PBPC primed with cyclophosphamide and GM-CSF.

CONCLUSION

In patients with advanced breast cancer responsive to cytotoxic chemotherapy, tumor-cell contamination is not increased in PBPC collected after 5 or 7 days priming with G-CSF and appears similar to that seen when PBPC are primed with cyclophosphamide followed by GM-CSF.

Immunocytochemical analysis of tumor cells in pre- and post-culture peripheral blood progenitor cell collections from breast cancer patients

We examined peripheral blood progenitor cell (PBPC) collections and CD(34+)-selected fractions cultured in PIXY321, a fusion protein comprising analog interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) domains, for the presence of contaminating tumor cells from 14 patients with advanced-stage breast cancer. Five of the 14 (36%) pre-culture PBPC specimens contained immunocyto-chemically (ICC)-detectable tumor cells using two different cocktails of monoclonal antibodies (mAbs). After 10 days in culture with PIXY321, the CD(34+)-selected fractions showed a median 23.6-fold expansion of hematopoietic cells. No ICC-positive tumor cells were detected in any post-culture specimens. We conclude that in vitro expansion of CD(34+)-selected PBPCs with PIXY321 can expand hematopoietic cell populations apparently without risk of expanding contaminating breast cancer cell populations.

Immunocytochemical detection of tumor cells in bone marrow and peripheral blood stem cell collections from patients with ovarian cancer

High-dose chemotherapy (HDC) followed by autologous hematopoietic reconstitution is an experimental treatment option for patients with epithelial ovarian cancer. However, the incidence of occult ovarian tumor cell involvement in autologous bone marrow (BM) or peripheral blood stem cell (PBSC) autografts has not been widely investigated. We used a highly sensitive immunocytochemical (ICC) procedure that detects occult blood-borne tumor micrometastases. We analyzed 24 BM specimens (15 obtained during therapy and 9 harvest samples) and seven PBSC specimens from 22 patients with ovarian cancer. Overall, ICC analysis detected immunostained tumor cells in 10 of 23 evaluable BM specimens (43%) from 9 of 19 patients (47%). One of 9 (11%) harvest samples contained tumor cells. Only one of the 10 ICC-positive BM specimens had tumor cells detected by routine histopathological analysis. ICC-detectable tumor cells were cleared from the marrow of two patients during chemotherapy. None of the seven PBSC specimens contained tumor cells. We conclude that ovarian cancer micrometastases have the potential to contaminate BM, as is also the case in patients with other epithelial malignancies. In the limited number of specimens analyzed, PBSC harvests appeared to provide a less tumor-contaminated source of hematopoietic stem cells for autologous transplantation.

Absence of breast cancer cells in a single-day peripheral blood progenitor cell collection after priming with cyclophosphamide and granulocyte-macrophage colony-stimulating factor

The effect of priming on occult tumor cell involvement of peripheral blood (PB) and PB progenitor cell (PBPC) collections is poorly characterized. Using sensitive immunocytochemistry (ICC) and tumor clonogenic assays (TCA) specific for epithelial-derived tumor cells, hematopoietic specimens were analyzed for PBPC and occult tumor cell involvement in 28 patients with chemotherapy-sensitive stage IIIB or IV breast cancer. Before PBPC priming, tumor was detected by ICC in PB of 1 of 23 (4%) patients and in bone marrow (BM) harvests of 4 of 27 (15%) patients. Fifteen days after cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF) priming, 2 of 28 (7%) patients had ICC-positive PBPC collections. The median amplification of CD34+ PBPC during this time was over 19-fold (range, < 1 to 199). One patient had pretreatment tumor involvement of both PB and BM. One patient grew tumor colonies in TCA; the PB and BM were ICC- and TCA-positive, but the PBPC collection was ICC-positive and TCA-negative. After cytoreduction with conventional-dose chemotherapy, patients with advanced breast cancer and histologically negative BM biopsy specimens have rare tumor cell involvement of PB and BM. Despite effective PBPC priming with cyclophosphamide and GM-CSF, clonogenic breast cancer cells were not found in the PBPC collection performed on day 15.

Bone marrow micrometastases in chemotherapy-responsive advanced breast cancer: effect of ex vivo purging with 4-hydroperoxycyclophosphamide

Tumor contamination of hematopoietic stem cell grafts may influence the outcome of breast cancer patients treated with high-dose chemotherapy. The goals of this study were: (a) to evaluate the prevalence of tumor contamination of bone marrow (BM) harvests in patients responding to systemic chemotherapy; (b) to evaluate reduction of BM tumor contamination by ex vivo purging with 4-hydroperoxycyclophosphamide (4HC); and (c) to compare the tumor contamination of peripheral blood progenitor cell collections and BM in advanced-stage breast cancer patients designated for peripheral blood progenitor cell infusion. We evaluated pre- and post-4HC purge BM specimens from 20 patients for tumor contamination using immunocytochemistry and for in vitro growth potential of tumor cells using a tumor cell clonogenic assay. Pre-4HC purge BM specimens from 15 of 20 (75%) patients were immunocytochemistry and tumor cell clonogenic assay negative. The remaining 5 BM specimens were immunocytochemistry positive, but only 3 of 5 specimens were tumor cell clonogenic assay positive. In vitro tumor colony growth was not observed in any post-4HC purge BM specimens. We also evaluated nine patients with bone or BM metastases from the start of induction chemotherapy. We found less tumor involvement of peripheral blood progenitor cell collections than of simultaneously obtained bone marrow aspirates. We conclude that bone marrow micrometastases occur with low frequency in women with chemotherapy-sensitive breast cancer and that ex vivo purging with 4HC may render tumor cells nonviable.

Immunohistologic detection of prostate cancer pelvic lymph node micrometastases: correlation to preoperative serum prostate-specific antigen

OBJECTIVE

To test the hypothesis that prostate cancer lymph node (LN) micrometastases, undetected by standard histology, might be found using sensitive immunohistologic methods and may correlate to preoperative prostate-specific antigen (PSA) levels.

METHOD

Archival paraffin blocks of pelvic lymphadenectomy specimens from radical prostatectomy were blindly submitted for immunostaining using pan-cytokeratin monoclonal antibody SB-3, as well as antibodies directed against PSA. Automated immunostaining was performed on a Ventana Medical Systems 320 immunostainer. As a positive control, 7 cases with known nodal metastases by standard histology were blindly analyzed and all has detectable micrometastases by this methodology.

RESULTS

For 13 patients with PSA < 10.1 (8%) had LN micrometastases detected. For 10 patients with PSA between 10 and 20 and for 9 patients with PSA > 20, no occult metastases were detected. We did find previously undetected prostate cancer (CaP) LN micrometastases in 1 of 32 (3%) clinically localized prostate cancer patients who had undergone radical prostatectomy. In many LNs, cytokeratin stains cross-reacted and stained individual plasma cells, whereas in the positive metastatic case, a cluster/nest of CaP cells were reactive. To the unfamiliar observer, the pitfall of false-positive results because of nonspecific cytokeratin staining must be considered. These results are in exact agreement with another recent study which also found only a 3 percent incidence of unsuspected pelvic lymph node micrometastases in clinically localized CaP utilizing similar methods.

CONCLUSIONS

Our hypothesis was not substantiated: LN micrometastases were uncommon and did not correlate to serum PSA. Unlike studies with breast cancer, occult micrometastatic nodal disease not appreciated by standard methods appears to be uncommon in clinically localized prostatic carcinoma.

Detection and viability of tumor cells in peripheral blood stem cell collections from breast cancer patients using immunocytochemical and clonogenic assay techniques

Although peripheral blood stem cell collections (PBSC) are thought to have less tumor involvement than bone marrow (BM), the incidence of circulating tumor cells in patients with breast cancer has not been widely investigated. We prospectively investigated the incidence and viability of tumor cell involvement in PBSC and BM collections from breast cancer patients undergoing high-dose chemotherapy/hematopoietic stem cell transplantation. Paired samples of PBSC and BM from 48 patients were analyzed using an immunocytochemical technique that detects one epithelial-derived tumor cell per 5 x 10(5) mononuclear cells. Immunostained tumor cells were detected in 9.8% (13/133) PBSC specimens from 9/48 (18.7%) patients and in 62.3% (38/61) BM specimens from 32/48 (66.7%) patients, a significantly higher rate than in PBSC (P < .005). The geometric mean concentration of tumor cells in contaminated PBSC specimens was 0.8/10(5) mononuclear cells (range 0.33 to 2.0/10(5)) compared with 22.9/10(5) mononuclear cells in BM (range 1 to 3,000/10(5), P < .0001). In culture experiments, clonogenic tumor colonies grew in 21/26 immunocytochemically positive specimens. No tumor colony growth was detected in 30/32 immunocytochemically negative specimens. Immunocytochemical detection of tumor involvement in BM and PBSC correlated significantly with in vitro clonogenic growth (P < .0001). We conclude that PBSC contain fewer tumor cells than paired BM specimens from patients with advanced breast cancer and that these tumor cells appear to be capable of clonogenic growth in vitro.

The Risk of Tumor Cell Contamination in Peripheral Blood Stem Cell Collections

Peripheral blood stem cell (PBSC) reinfusions are being used with increasing frequency in lieu of, or in addition to, autologous bone marrow transplantation (ABMT) to rescue cancer patients from the myeloablative effects of high-dose chemotherapy. However, the incidence and quantity of tumor cell contamination in PBSC collections has not been widely investigated. This paper reviews the existing data and presents new information to demonstrate that tumor cells are detectable in PBSC harvests from patients with a variety of malignancies. Furthermore, their presence in peripheral blood may have prognostic and clinical significance. Areas of future research and applications for PBSC technologies are also discussed.

Lack of antibody formation during long-term subcutaneous treatment with the somatostatin analogue octreotide in acromegaly

Serum samples from 13 patients with active acromegaly on long-term sc treatment with octreotide (SMS 201-995, 1-36 months, mean daily dose 285 micrograms) were taken 12 h after the injection of their regular evening doses. Octreotide assay was performed using 125I-Tyr-SMS and a polyclonal rabbit anti-serum. For assessment of antibody formation both serum coated charcoal adsorption (adsorption of free octreotide) and polyethylene glycol precipitation (precipitation of IgG complexes) were used. The mean binding percentage in the patients proved to be similar to that of 5 healthy volunteers (p greater than 0.10). No specific binding was detected, whatever method used. No correlation was found between the binding percentages and octreotide serum levels, duration of octreotide treatment or daily octreotide dose (p greater than 0.10). These results strongly suggest that clinically relevant endogenous antibody formation is not a frequent event during long-term sc treatment of acromegalic patients with octreotide.

Progressive multifocal leukoencephalopathy and retroviral encephalitis in acquired immunodeficiency syndrome

Antigens of human polyomaviruses, the etiologic agents of progressive multifocal leukoencephalopathy (PML), and of human immunodeficiency virus were localized in paraffin sections from brains of six patients who died with the acquired immunodeficiency syndrome. Immunostaining revealed polyomaviral antigens in oligodendrocytes and in some astrocytes. Human immunodeficiency (retro) virus antigens were immunostained in mononuclear macrophages, glial cells, and vascular endothelial cells. Both viral types were found ultrastructurally. The lesions of PML were more destructive than is usually seen in cases without the acquired immunodeficiency syndrome. The retroviral encephalitis could have occurred before the onset of PML. However, a secondary retroviral encephalitis could have resulted if the monocytes responding to an initial polyomaviral lesion were already infected with human immunodeficiency virus before they differentiated into macrophages.

N-azamonobactams. 1. The synthesis of some 3-substituted N-azamonobactam derivatives

Ring closure of the N-(tert-butyloxycarbonyl)-L-serine 2-(diphenylmethylene)hydrazide (10a) and the corresponding L-threonine derivative (10b) gave good yields of the beta-lactams 11a and 11b. Catalytic hydrogenation afforded the corresponding N-amino beta-lactams 12a and 12b. These compounds were then further transformed into 3-(S)-[[(2-amino-4-thiazolyl)-(Z)-(methoxyimino)acetyl]amino-2-oxo-1- azetidinyl]sulfamic acid analogs 18, 23, and 30a and 30b. None of these compounds exhibited any interesting biological activity.

Follow-up pathology of cranial computed tomography: pitfalls in clinical-radiological evaluation

Interpretation of cranial computed tomography in five patients and angiography in one of these patients contributed significantly to primary clinical diagnoses and management; however, the diagnoses were incorrect. The lesions in the radiographic studies were correlated with classical clinical findings. Associated and generally unappreciated clinical or radiographic findings also were present and could have lead to reconsideration of at least some of the primary diagnoses. The unusual or unique presentations resulting in underdiagnosis or overdiagnosis lead to nonbeneficial or improper care. Cerebrovascular and infectious diseases found in most of these cases are recognized as common areas of diagnostic difficulty by previous and present follow-up pathological studies.