Genomic characterization of HER2-positive breast cancer and response to neoadjuvant trastuzumab and chemotherapy-results from the ACOSOG Z1041 (Alliance) trial

Background

HER2 (ERBB2) gene amplification and its corresponding overexpression are present in 15-30% of invasive breast cancers. While HER2-targeted agents are effective treatments, resistance remains a major cause of death. The American College of Surgeons Oncology Group Z1041 trial (NCT00513292) was designed to compare the pathologic complete response (pCR) rate of distinct regimens of neoadjuvant chemotherapy and trastuzumab, but ultimately identified no difference.

Patients and methods

In supplement to tissues from 37 Z1041 cases, 11 similarly treated cases were obtained from a single institution study (NCT00353483). We have extracted genomic DNA from both pre-treatment tumor biopsies and blood of these 48 cases, and performed whole genome (WGS) and exome sequencing. Coincident with these efforts, we have generated RNA-seq profiles from 42 of the tumor biopsies. Among patients in this cohort, 24 (50%) achieved a pCR.

Results

We have characterized the genomic landscape of HER2-positive breast cancer and investigated associations between genomic features and pCR. Cases assigned to the HER2-enriched subtype by RNA-seq analysis were more likely to achieve a pCR compared to the luminal, basal-like, or normal-like subtypes (19/27 versus 3/15; P = 0.0032). Mutational events led to the generation of putatively active neoantigens, but were overall not associated with pCR. ERBB2 and GRB7 were the genes most commonly observed in fusion events, and genomic copy number analysis of the ERBB2 locus indicated that cases with either no observable or low-level ERBB2 amplification were less likely to achieve a pCR (7/8 versus 17/40; P = 0.048). Moreover, among cases that achieved a pCR, tumors consistently expressed immune signatures that may contribute to therapeutic response.

Conclusion

The identification of these features suggests that it may be possible to predict, at the time of diagnosis, those HER2-positive breast cancer patients who will not respond to treatment with chemotherapy and trastuzumab.

ClinicalTrials.gov identifiers

NCT00513292, NCT00353483.

Abstract P4-02-04: Using ultrasound findings to predict high tumor-infiltrating lymphocytes in triple negative breast cancer

Purpose Previous clinical data showed that high tumor-infiltrating lymphocytes (TILs) indicated a good prognosis in triple negative breast cancer (TNBC) and suggested that TNBC with TILs responded well to immunotherapy. Breast ultrasound is a safe inspection method without any radiation exposure. Therefore, we investigated whether ultrasound findings can predict high TILs in TNBC.

Patients and Methods The TNBC patients who underwent surgery at Mitsui Memorial Hospital, Tokyo, Japan, from 2009 to 2015, including those who underwent neo adjuvant chemotherapy (NAC), were selected for this study. The pre-treatment ultrasound findings were used retrospectively, and we compared the shape, margin, homogeneity of internal echoes, posterior features, and growth pattern of the lesions. Regarding shape, we classified the ultrasound findings as “round”, “oval”, “lobulated”, “irregular”, and “other” in accordance with The Japan Associations of Breast and Thyroid Sonology. Similarly, we classified the margins as "circumscribed" or "well-defined and smooth", "well-defined and rough", "indistinct" and "obscure". We used “homogeneous” and “heterogeneous” internal echoes. In terms of posterior features, we used the “accentuation”, “not changing”, “attenuating” and “shadowing” categories. By referring to previous report, we classified four types of growth patterns, i.e., "growing along the mammary ducts", "expansive growth pattern", "irregularly shaped mass with retracting surrounding tissue" and "other". Two pathologists evaluated stromal TILs, which were located between the cancer nests, by surgical specimens or needle biopsies of those who underwent NAC. Then the TILs were classified into four groups: “absent”, “weak”, “moderate”, and “dense”. “Absent” indicated that there were no lymphocytes in the stroma. “Weak”, “moderate” and “dense” indicated that lymphocytes occupied about 1–40%, 40–75% and 75%–100% area in the stroma, respectively. We analyzed ultrasound findings and TILs with the χ -square test.

Results A total of 97 lesions and 95 female TNBC patients were validated. The median age was 62 years old (range, 32–88 years). Of the total, 37 patients underwent NAC. The degree of “absent” TILs was 5 lesions, “weak” was 58, “moderate” was 22, and “dense” was 12 lesions. In the ultrasound findings, the shape categories “round,” “oval,” and “lobulated” were more "dense" TILs (n=12, 100%) than others (n=47, 55.3%) (p = 0.002). The "circumscribed" and "well-defined and rough" margins were found to be more “dense” TILs (n=11, 91.7%) than the other TILs (n=49, 57.6%) (p=0.020). “Accentuating” posterior echoes were more “dense” and “moderate” TILs (n=23, 67.6%) than “weak” and “absent” TILs (n=25, 39.7%) (p=0.009). The lesions with expansively growing pattern showed higher rate “dense” and “moderate” TILs (n=20, 58.8%) than “weak” and “absent” TILs (n=20, 31.7%) (p=0.010). There were no significant differences in internal echoes.

Conclusion We determined that ultrasound findings of round, oval or lobulated shape, accentuating posterior echoes and expansively growing pattern could predict the presence of high TILs. Thus, the safe, low-cost, and radiation-free ultrasound examination was recommended for predicting high TILs and prognosis.

Citation Format: Inagaki M, Ota D, Tsuji M, Kobayashi Y, Mori M, Fukuuchi A. Using ultrasound findings to predict high tumor-infiltrating lymphocytes in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-04.

Ki67 Proliferation Index as a Tool for Chemotherapy Decisions During and After Neoadjuvant Aromatase Inhibitor Treatment of Breast Cancer: Results From the American College of Surgeons Oncology Group Z1031 Trial (Alliance)

Purpose

To determine the pathologic complete response (pCR) rate in estrogen receptor (ER) –positive primary breast cancer triaged to chemotherapy when the protein encoded by the MKI67 gene (Ki67) level was > 10% after 2 to 4 weeks of neoadjuvant aromatase inhibitor (AI) therapy. A second objective was to examine risk of relapse using the Ki67-based Preoperative Endocrine Prognostic Index (PEPI).

Methods

The American College of Surgeons Oncology Group (ACOSOG) Z1031A trial enrolled postmenopausal women with stage II or III ER-positive (Allred score, 6 to 8) breast cancer whose treatment was randomly assigned to neoadjuvant AI therapy with anastrozole, exemestane, or letrozole. For the trial ACOSOG Z1031B, the protocol was amended to include a tumor Ki67 determination after 2 to 4 weeks of AI. If the Ki67 was > 10%, patients were switched to neoadjuvant chemotherapy. A pCR rate of > 20% was the predefined efficacy threshold. In patients who completed neoadjuvant AI, stratified Cox modeling was used to assess whether time to recurrence differed by PEPI = 0 score (T1 or T2, N0, Ki67 < 2.7%, ER Allred > 2) versus PEPI > 0 disease.

Results

Only two of the 35 patients in ACOSOG Z1031B who were switched to neoadjuvant chemotherapy experienced a pCR (5.7%; 95% CI, 0.7% to 19.1%). After 5.5 years of median follow-up, four (3.7%) of the 109 patients with a PEPI = 0 score relapsed versus 49 (14.4%) of 341 of patients with PEPI > 0 (recurrence hazard ratio [PEPI = 0 v PEPI > 0], 0.27; P = .014; 95% CI, 0.092 to 0.764).

Conclusion

Chemotherapy efficacy was lower than expected in ER-positive tumors exhibiting AI-resistant proliferation. The optimal therapy for these patients should be further investigated. For patients with PEPI = 0 disease, the relapse risk over 5 years was only 3.6% without chemotherapy, supporting the study of adjuvant endocrine monotherapy in this group. These Ki67 and PEPI triage approaches are being definitively studied in the ALTERNATE trial (Alternate Approaches for Clinical Stage II or III Estrogen Receptor Positive Breast Cancer Neoadjuvant Treatment in Postmenopausal Women: A Phase III Study; clinical trial information: NCT01953588).

Abstract PD6-02: The genomics of response to neoadjuvant trastuzumab and chemotherapy in HER2-positive breast cancer – Results from the ACOSOG Z1041 (Alliance) trial

Support: Alliance U10CA180821; Alliance Statistical Center grant U10CA180882; ACOSOG grant U10CA76001

HER2 gene amplification and its corresponding overexpression are present in approximately 12% of invasive breast cancers. While HER2-targeted agents (e.g. trastuzumab, pertuzumab, and lapatinib) are effective treatments, resistance remains a major cause of death from HER2-positive breast cancer. Mechanisms of resistance are poorly understood. Without a molecular understanding of these mechanisms, therapeutic advances will be delayed. We have generated molecular profiles of primary HER2-positive breast cancers treated on a neoadjuvant clinical trial, and compared features associated with response to treatment.

The American College of Surgeons Oncology Group (ACOSOG) Z1041 trial in HER2-positive breast cancer was designed to compare the pathologic complete response (pCR) rate of a regimen of paclitaxel and trastuzumab, followed by trastuzumab administered with fluorouracil, epirubicin, and cyclophosphamide (FEC-75) to a regimen of FEC-75 alone followed by paclitaxel and trastuzumab. The trial identified no difference in pCR rates between the regimens (Buzdar et al., The Lancet Oncology 2013). In supplement to the tissues obtained from 37 of the patients enrolled in the Z1041 trial, an additional 11 cases were obtained from a single institution study (201101961) of patients treated with neoadjuvant trastuzumab that had pre-treatment core biopsies suitable for genomic studies.

We have extracted genomic DNA from both pretreatment tumor biopsies and blood samples of these 48 patients and performed whole genome (WGS) and exome sequencing. Coincident with these efforts, we have extracted high quality RNA from 42 of the 48 biopsies, and have processed RNA-seq profiles of the tumors. Among patients in this cohort, 24 (50%) achieved a pCR. Because no difference was observed between arms of the Z1041 trial, patients with or without a pCR were directly compared without adjusting for treatment regimen.

On average, each tumor and normal sample pair were sequenced to a depth of 49.4x and 32.5x by WGS respectively. In total, 15,027 candidate somatic variants were identified in known genes, including 11,606 missense, 860 nonsense, and 418 frameshift insertions or deletions. Preliminary results identified mutations in HER2 that were associated with the failure to achieve pCR in several cases. Furthermore, tumors assigned to the HER2-enriched subtype by RNA-seq analysis were more likely to achieve a pCR (19 compared to 8) than tumors with genomic features indicative of either the luminal or basal-like subtypes (3 compared to 12); a significant difference in the proportion of cases that achieve pCR (Fisher's exact test p-value = 0.0032). The identification of these features suggests that it may be possible to predict, at the time of diagnosis, those patients who will not respond to the current standard of care for HER2-positive breast cancer.

Citation Format: Lesurf R, Griffith O, Griffith M, Watson MA, Hoog J, Ellis MJ, Ota D, Suman VJ, Meric-Bernstam F, Leitch AM, Boughey JC, Unzeitig G, Buzdar AU, Hunt KK, Mardis ER. The genomics of response to neoadjuvant trastuzumab and chemotherapy in HER2-positive breast cancer – Results from the ACOSOG Z1041 (Alliance) trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD6-02.

Comprehensive genomic studies: emerging regulatory, strategic, and quality assurance challenges for biorepositories

As part of the molecular revolution sweeping medicine, comprehensive genomic studies are adding powerful dimensions to medical research. However, their power exposes new regulatory, strategic, and quality assurance challenges for biorepositories. A key issue is that unlike other research techniques commonly applied to banked specimens, nucleic acid sequencing, if sufficiently extensive, yields data that could identify a patient. This evolving paradigm renders the concepts of anonymized and anonymous specimens increasingly outdated. The challenges for biorepositories in this new era include refined consent processes and wording, selection and use of legacy specimens, quality assurance procedures, institutional documentation, data sharing, and interaction with institutional review boards. Given current trends, biorepositories should consider these issues now, even if they are not currently experiencing sample requests for genomic analysis. We summarize our current experiences and best practices at Washington University Medical School, St Louis, MO, our perceptions of emerging trends, and recommendations.

Whole-genome analysis informs breast cancer response to aromatase inhibition

To correlate the variable clinical features of estrogen receptor positive (ER+) breast cancer with somatic alterations, we studied pre-treatment tumour biopsies accrued from patients in a study of neoadjuvant aromatase inhibitor (AI) therapy by massively parallel sequencing and analysis. Eighteen significantly mutated genes were identified, including five genes (RUNX1, CBFB, MYH9, MLL3 and SF3B1) previously linked to hematopoietic disorders. Mutant MAP3K1 was associated with Luminal A status, low grade histology and low proliferation rates whereas mutant TP53 associated with the opposite pattern. Moreover, mutant GATA3 correlated with suppression of proliferation upon AI treatment. Pathway analysis demonstrated mutations in MAP2K4, a MAP3K1 substrate, produced similar perturbations as MAP3K1 loss. Distinct phenotypes in ER+ breast cancer are associated with specific patterns of somatic mutations that map into cellular pathways linked to tumor biology but most recurrent mutations are relatively infrequent. Prospective clinical trials based on these findings will require comprehensive genome sequencing.

Abstract LB-423: Whole genome comparisons of pre- and post- aromatase inhibitor treatment in estrogen receptor positive breast cancer

Background: Estrogen receptors are over-expressed in around 70% of breast cancer cases. The genetic changes that occur during aromatase inhibitor (AI) treatment are not well understood and may differ depending upon the patient's response phenotype. Methods: We performed whole genome sequencing (WGS) of matched blood, pre-treatment, and post-treatment biopsy samples from 22 estrogen receptor positive breast cancer patients treated with neoadjuvant aromatase inhibitors. For 5 cases, we performed the whole genome sequencing (WGS) on patients’ matched normal, two pre AI-treatment, and two post AI-treatment DNA isolates from biopsy samples. We validated all putative coding and non-coding somatic mutations using deep sequencing. By comparing the validated somatic mutations from pre- and post- AI treatment biopsy samples, we were able to determine the alterations in the tumor genomes. In every case we defined the clonal architecture of each pair of pre-treatment and post-treatment biopsy samples by comparing the variant allele frequencies from thousands of validated somatic mutations. Results: Comparisons of the two pre AI-treatment biopsy samples from the same patient indicates that the variant allele frequencies of mutations showed high concordances in all 5 cases, 0.74 to 0.95 range of correlation coefficient. Only a small percentage of somatic mutations were detected in one pre-treatment sample and not the other (4.65% overall). In comparing the somatic variations between pre-treatment and matched post-treatment biopsy samples in 22 cases, we found that patients with good clinical response to AI treatment retained known driver mutations only in their pre-treatment tumors. Conversely, those patients with poor clinical response presented new driver mutations in their post-treatment samples. Furthermore, the variant allele frequency for most mutated genes decreased in post AI treatment samples for patients with good AI treatment response; on the contrary, the variant allele frequency increased for patients with poor clinical response. Conclusions: From WGS of matched normal, pre-treatment, and post-treatment biopsy samples, we identified new driver genes mutated in patients with poor clinical response, while patients with good clinical response had lost mutated driver genes in their post-treatment biopsy samples. The genetic landscape revealed by WGS of pre-treatment and post-treatment biopsy samples reveals mutational repertoires are remodeled by AI therapy. This finding suggests deep sequencing of AI treated samples will be necessary to reveal the complete complement of mutations present in a patient's tumor.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-423. doi:1538-7445.AM2012-LB-423

Use of the National Cancer Data Base to develop clinical trials accrual targets that are appropriate for minority ethnicity patients

BACKGROUND

Disparities in cancer outcome among different subsets of the American population related to ethnic background have been well documented. Clinical trials represent the most powerful strategy for improving cancer treatments, but racial and ethnic minority patients are frequently underrepresented among patients accrued to these protocols. Proof of comparable efficacy for a promising cancer therapy in different groups of patients requires diversity in the clinical trial populations so that study results will be generalizable. Appropriate targets for accrual of minority ethnicity patients have not previously been defined.

METHODS

The National Cancer Database (NCDB) is maintained jointly by the American Cancer Society and the American College of Surgeons. Information submitted by tumor registries throughout the United States represents an estimated 70% of newly diagnosed cancer cases. The authors analyzed NCDB reports on ethnic distribution of patients with breast, prostate, nonsmall cell lung, and colorectal cancer, stratified by stage of disease at diagnosis.

RESULTS

African Americans with cancer of the breast and prostate had the most notable patterns of disproportionate representation among populations with advanced-stage disease. The authors compiled a table of suggested accrual targets for selected solid-organ cancers based on NCDB stage-specific reports.

CONCLUSIONS

Clinical trial results will be more meaningful if participating patients reflect the site- and stage-specific populations that are under study. The authors recommended that clinical trial investigators incorporate accrual targets for minority ethnicity populations into the study design.

Crossover trial for lipid abnormality in postmenopausal breast cancer patients during selective estrogen receptor modulators (SERMs) administrations

The objective of this study was to evaluate the different profiles of serum lipids resulting from the administration of selective estrogen receptor modulators (SERMs). Postmenopausal primary breast cancer patients (n = 197) with node-negative, hormone receptor-positive who were treated at our department or in other related medical institutions from April 1997 through March 2001 were given adjuvant therapy. The adjuvant therapy included 1 year's administration of tamoxifen (TAM) 20 mg or toremifene (TOR) 40 mg. The profiles of serum lipids such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL) and triglyceride (TG) were observed. After 1 year administration TC had significantly decreased (p < 0.001) both in the TAM group and the TOR group, but no significant difference was found between these groups (p = 0.249). HDL had significantly decreased in the TAM group (p < 0.001), while it had significantly increased in the TOR group (p < 0.001), and a significant difference was found between the groups (p < 0.001). TG had significantly increased in the TAM group (p < 0.001) but significantly decreased in the TOR group (p < 0.001). The medication was switched in those who still had abnormal lipid metabolism and given to them for another year. After 1 year from the crossover TC and HDL had increased to the levels of before administration (p < 0.001) and TG had decreased in those (n = 57) whose medication was switched from TAM to TOR. While TC had decreased and TG had increased in those (n = 23) whose medication was switched from TOR to TAM (p < 0.001). The above findings have suggested that TOR provides better profiles of lipid metabolism than TAM.

Feasibility of breast duct lavage performed by a physician extender

BACKGROUND

The safety and feasibility of ductal lavage (DL), a risk-assessment tool utilizing a minimally invasive technique that permits sampling of breast duct epithelium, performed primarily by a nurse practitioner (NP), was studied prospectively.

METHODS

Women at high risk for breast cancer with a normal clinical breast exam and mammogram were enrolled. Nipple aspirate fluid (NAF)-yielding ducts were identified, cannulated, and lavaged primarily by an NP in collaboration with a breast surgeon. Samples with sufficient cellularity were categorized as benign, mild atypia, marked atypia, or malignant. Pain and adverse events were recorded.

RESULTS

Thirty-seven women, with a mean age of 51.7 years, were enrolled. Thirty-one (83.8%) women yielded NAF and, of those, 28 (90.3%) had one or more ducts successfully cannulated. Of 65 lavaged ducts in these 28 women, cellularity was adequate for diagnosis in 44 (67.7%) samples. Cytologic findings were as follows: 24 benign, 15 mild atypia, 4 marked atypia, and 1 malignant. The procedure was well tolerated with a mean pain score of 3.2 (SD +/- 1.81). The most frequent adverse event was breast fullness, reported by 44.8% of the women. Two women with marked atypia were evaluated further and found to have intraductal papillomata. The woman with malignant cytology had ductal carcinoma in situ.

CONCLUSION

DL is a safe, generally well-tolerated procedure that can be performed successfully by a trained NP.

A comparison of laparoscopically assisted and open colectomy for colon cancer

BACKGROUND

Minimally invasive, laparoscopically assisted surgery was first considered in 1990 for patients undergoing colectomy for cancer. Concern that this approach would compromise survival by failing to achieve a proper oncologic resection or adequate staging or by altering patterns of recurrence (based on frequent reports of tumor recurrences within surgical wounds) prompted a controlled trial evaluation.

METHODS

We conducted a noninferiority trial at 48 institutions and randomly assigned 872 patients with adenocarcinoma of the colon to undergo open or laparoscopically assisted colectomy performed by credentialed surgeons. The median follow-up was 4.4 years. The primary end point was the time to tumor recurrence.

RESULTS

At three years, the rates of recurrence were similar in the two groups--16 percent among patients in the group that underwent laparoscopically assisted surgery and 18 percent among patients in the open-colectomy group (two-sided P=0.32; hazard ratio for recurrence, 0.86; 95 percent confidence interval, 0.63 to 1.17). Recurrence rates in surgical wounds were less than 1 percent in both groups (P=0.50). The overall survival rate at three years was also very similar in the two groups (86 percent in the laparoscopic-surgery group and 85 percent in the open-colectomy group; P=0.51; hazard ratio for death in the laparoscopic-surgery group, 0.91; 95 percent confidence interval, 0.68 to 1.21), with no significant difference between groups in the time to recurrence or overall survival for patients with any stage of cancer. Perioperative recovery was faster in the laparoscopic-surgery group than in the open-colectomy group, as reflected by a shorter median hospital stay (five days vs. six days, P<0.001) and briefer use of parenteral narcotics (three days vs. four days, P<0.001) and oral analgesics (one day vs. two days, P=0.02). The rates of intraoperative complications, 30-day postoperative mortality, complications at discharge and 60 days, hospital readmission, and reoperation were very similar between groups.

CONCLUSIONS

In this multi-institutional study, the rates of recurrent cancer were similar after laparoscopically assisted colectomy and open colectomy, suggesting that the laparoscopic approach is an acceptable alternative to open surgery for colon cancer.

Guidelines 2000 for colon and rectal cancer surgery

BACKGROUND

Oncologic resection techniques affect outcome for colon cancer and rectal cancer, but standardized guidelines have not been adopted. The National Cancer Institute sponsored a panel of experts to systematically review current literature and to draft guidelines that provide uniform definitions, principles, and practices.

METHODS

Methods were similar to those described by the American Society of Clinical Oncology in developing practice guidelines. Experts representing oncology and surgery met to review current literature on oncologic resection techniques for level of evidence (I-V, where I is the best evidence and V is the least compelling) and grade of recommendation (A-D, where A is based on the best evidence and D is based on the weakest evidence). Initial guidelines were drafted, reviewed, and accepted by consensus.

RESULTS

For the following seven factors, the level of evidence was II, III, or IV, and the findings were generally consistent (grade B): anatomic definition of colon versus rectum, tumor-node-metastasis staging, radial margins, adjuvant R0 stage, inadvertent rectal perforation, distal and proximal rectal margins, and en bloc resection of adherent tumors. For another seven factors, the level of evidence was II, III, or IV, but findings were inconsistent (grade C): laparoscopic colectomy; colon lymphadenectomy; level of proximal vessel ligation, mesorectal excision, and extended lateral pelvic lymph node dissection (all three for rectal cancer); no-touch technique; and bowel washout. For the other four factors, there was little or no systematic empirical evidence (grade D): abdominal exploration, oophorectomy, extent of colon resection, and total length of rectum resected.

CONCLUSIONS

The panel reports surgical guidelines and definitions based on the best available evidence. The availability of more standardized information in the future should allow for more grade A recommendations.

Distal margin requirements after preoperative chemoradiotherapy for distal rectal carcinomas: are < or = 1 cm distal margins sufficient?

BACKGROUND

Sphincter-sparing alternatives to abdominoperineal resection (APR) in the treatment of rectal cancer often are underused out of concern for inadequate distal margins and local failure. The present study addresses whether sphincter-sparing techniques with distal margins < or = 1 cm adversely influence oncological outcome in patients given preoperative chemoradiotherapy.

METHODS

Thirty-seven patients with rectal cancer < or = 8 cm from the anal verge were enrolled in the study. Preoperative external beam radiotherapy (5400 Gy) was administered together with continuous infusion of 5-fluorouracil (300 mg/m2/day). Surgical resection was performed in 36 patients with pathological assessment of tumor response and margins. Patients with sphincter-sparing resection and distal margins > 1 cm or < or = 1 cm and those who underwent APR were compared.

RESULTS

Thirty-six patients completed preoperative chemoradiotherapy, with successful sphincter-preservation in 28 patients. At a median follow-up of 33 months, there were 12 recurrences overall, which included 11 distant failures and four pelvic failures. Disease-free survival (DFS) was not different between those who had an APR compared with sphincter-sparing resection with distal margins < or = 1 cm. DFS was worse (P < .02) when radial margins were < or = 3 mm compared with > 3 mm.

CONCLUSIONS

Sphincter preservation is feasible in more than 75% of patients with tumors < or = 8 cm from the anal verge after preoperative chemoradiotherapy. Sphincter-sparing surgery with distal margins < or = 1 cm can be used without adversely influencing local recurrence or DFS. Limited radial margins (< or = 3 mm), however, are associated with increased disease recurrence.

[Two cases of malignancy-associated hypercalcemia from bone metastases of breast cancer successfully treated with combination therapy using pamidronate and calcitonin]

Two patients with malignancy-associated hypercalcemia from bone metastases of breast cancer, accompanied by consciousness disturbance, were treated by a combination therapy of pamidronate and salmon calcitonin. The cause of the hypercalcemia in both cases was thought to be expanded bone metastases, which induced a local osteolytic hypercalcemia (LOH). In the end, this regimen could not control the growth of the metastatic tumor, but it produced a more rapid and prolonged decrease in serum calcium level than a single agent, and resulted in lessened consciousness disturbance without adverse effects. Hypercalcemia is a life-threatening paraneoplastic syndrome which requires urgent medical treatment, since malignant hypercalcemia progresses very rapidly and induces several severe complications. In conclusion, this combination therapy was extremely effective for consciousness disturbance accompanying hypercalcemia due to widespread bone metastases of cancer.

Olfactory discrimination of amino acids in brown bullhead catfish

Olfactory discrimination of amino acids was investigated in brown bullhead catfish (Ameiurus nebulosus). Based on the magnitude of the observed food search activity of catfish conditioned to single amino acids, the tested compounds were classified as being detected by the catfish as equal to, similar to, or different from the conditioned stimulus. L-Proline (L-Pro)-conditioned brown bullhead catfish discriminated all amino acids from L-Pro, but catfish conditioned to L-valine (L-Val) and L-isoleucine (L-Ile) did not discriminate L-Val from L-Ile nor L-Ile from L-Val; however, all other amino acids tested were always discriminated from these two compounds. Catfish conditioned to L-alanine (L-Ala) discriminated basic, acidic and several neutral amino acids with long side-chains (LCNs) from L-Ala; however, they did not always discriminate L-Ala from all neutral amino acids with short side-chains (SCNs). The L-norleucine (L-nLeu)-conditioned fish responded to L-norvaline (L-nVal), L-methionine (L-Met) and L-Ala similarly to L-nLeu, indicating that these amino acids are detected as similar or identical to L-nLeu. L-nLeu was, however, discriminated from L-Ala in L-Ala-conditioned catfish. Interestingly, L-leucine (L-Leu) was discriminated from the conditioned stimuli, L-Ala, L-Ile and L-Val, indicating independent receptors for L-Leu. Although conditioned catfish discriminated other amino acids from L-arginine hydrochloride (L-Arg), in some tests they were unable to discriminate L-Arg from L-lysine hydrochloride (L-Lys). These results imply the existence of independent olfactory receptive pathways for: (i) L-Pro; (ii) basic amino acids (L-Arg and L-Lys); (iii) L-Leu; (iv) other neutral amino acids with branched side-chains (L-Ile and L-Val); (v) neutral amino acids with long linear side-chains (L-nLeu, L-nVal and L-Met); (vi) neutral amino acids with short side-chains; and (vii) amino acids with sulfhydryl groups (L-Cys and L-homoCys).

Neuronal and glial cell types revealed by NADPH-diaphorase histochemistry in the retina of a teleost fish, the grass goby (Zosterisessor ophiocephalus, Perciformes, Gobiidae)

The grass goby is a mud-burrowing fish with a rich retinal vasculature appropriate to its hypoxic habitat. NADPH-diaphorase histochemistry was performed on retinal sections and wholemounts to reveal cells that contain nitric oxide synthase and so may be presumed to synthesise nitric oxide, a gaseous intercellular messenger with many roles including vasodilation. Structures that were consistently stained by this method included cone ellipsoids, horizontal cells, Müller cells and their processes, large displaced ganglion cells in the inner nuclear layer (identified by their axons), large interstitial ganglion cells in the inner plexiform layer, and capillary endothelial cells. In wholemounts, horizontal cells were seen to form a regular pattern, contacting each other at their dendritic terminals. Some cells in the ganglion cell layer were weakly stained, but stained bipolar and amacrine cells were not seen. The diaphorase-positive large ganglion cells all formed large, sparsely branched dendritic trees, arborizing near the scleral border of the inner plexiform layer. The displaced and interstitial cells seemed to belong to distinct morphological types, the interstitial cells having smaller somata and trees. Analysis of their spatial distributions in one representative retina confirmed this: the displaced cells formed a highly regular mosaic with a mean spacing (nearest-neighbour distance) of 303 microm, whereas the interstitial cells formed a separate mosaic, almost as regular but with a smaller mean spacing of 193 microm, rising to 217 microm in a sample that excluded the area retinae temporalis. Spatial correlogram analysis showed that these two mosaics were spatially independent. Nitric oxide probably has many roles in the retina. The presence of its synthetic enzyme in Müller cells, which communicate with retinal blood vessels, is consistent with a role in the control of retinal blood flow. Its function in large, mosaic-forming retinal ganglion cells is unknown.

Virtual reality in surgical education

Virtual reality (VR) is an emerging technology that can teach surgeons new procedures and can determine their level of competence before they operate on patients. Also VR allows the trainee to return to the same procedure or task several times later as a refresher course. Laparoscopic surgery is a new operative technique which requires the surgeon to observe the operation on a video-monitor and requires the acquisition of new skills. VR simulation could duplicate the operative field and thereby enhance training and reduce the need for expensive animal training models. Our preliminary experience has shown that we have the technology to model tissues and laparoscopic instruments and to develop in real time a VR learning environment for surgeons. Another basic need is to measure competence. Surgical training is an apprenticeship requiring close supervision and 5-7 years of training. Technical competence is judged by the mentor and has always been subjective. If VR surgical simulators are to play an important role in the future, quantitative measurement of competence would have to be part of the system. Because surgical competence is "vague" and is characterized by such terms as "too long, too short" or "too close, too far," it is possible that the principles of fuzzy logic could be used to measure competence in a VR surgical simulator. Because a surgical procedure consists of a series of tasks and each task is a series of steps, we will plan to create two important tasks in a VR simulator and validate their use. These tasks consist of laparoscopic knot tying and laparoscopic suturing. Our hypothesis is that VR in combination with fuzzy logic can educate surgeons and determine when they are competent to perform these procedures on patients.

Chemoradiation therapy for anal cancer: radiation plus continuous infusion of 5-fluorouracil with or without cisplatin

Chemoradiation therapy for anal cancer was carried out in 58 patients using low-dose, continuous infusion of 5-fluorouracil (5-FU) with or without continuous infusion of cisplatin (cDDP) and external beam irradiation (chemoXRT). Thirty-nine patients received 5-FU chemoXRT resulting in a local control rate of 50% in those receiving a total dose of < 45 Gy, 73% for those receiving 50-54 Gy, and 83% for those receiving > 60 Gy. The actuarial local control rate at 2 years was 77% after chemoXRT alone; overall local control was 67% at 5 years. In 18 patients receiving 5-FU plus cisplatin with radiation doses of 54-55 Gy, actuarial local control was 85% at 2 years. Fifteen patients failed chemoXRT, 13 of whom had abdominoperineal resection for salvage; the overall local control rate was 93% (54/58). The actuarial survival at 5 years was 81% for the 5-FU chemoXRT group and 94% at 2 years for the 5-FU plus cisplatin chemoXRT group; median follow-up was 54 and 20 months, respectively. Diarrhea and nausea were the most frequent early reactions and were ameliorated by limiting the duration of chemotherapy to 5 days/week and by using XRT techniques to exclude the small bowel from the radiation portal. Serious late radiation complications have not been observed and may be related to XRT fractionation and the use of protracted chemotherapy infusion. The absence of late morbidity coupled with the high local control rate by the use of this chemoXRT program is an area to investigate for improving the therapeutic ratio for the treatment of anal cancers.

Right and left ventricular function after cardiac transplantation. Changes during and after rejection

BACKGROUND

Attempts to identify noninvasive markers of ventricular dysfunction accompanying acute rejection have been hampered by a lack of detailed simultaneous hemodynamic data. Therefore, we prospectively performed serial monitoring of detailed left and right heart hemodynamic parameters in cardiac transplant recipients at the time of routine endomyocardial biopsy to better define the physiology of the allograft heart during and after acute rejection.

METHODS AND RESULTS

To better assess the pathophysiology of the rejection process, 18 cardiac transplant patients were prospectively studied by serial right heart micromanometer catheterization and digital image processing at the time of routine endomyocardial biopsy. Eleven patients had 18 episodes of rejection. Studies of baseline (negative biopsy preceding rejection), rejection (acute moderate rejection), and resolved (first negative biopsy after rejection) states were compared. Seven patients who did not experience an episode of rejection served as the control group. Right ventricular minimum and end-diastolic pressures increased from baseline values of 0.9 +/- 3.2 and 6.9 +/- 3.7 mm Hg, respectively, to 3.2 +/- 5.5 and 9.9 +/- 6.6 mm Hg, respectively, with rejection (both variables, p less than 0.05) and remained elevated despite histological resolution of rejection (4.3 +/- 5.5 and 10.0 +/- 7.1 mm Hg, respectively; p less than 0.05 for both variables compared with baseline values). Concurrently, right ventricular end-diastolic volumes (133 +/- 29, 119 +/- 27, and 114 +/- 30 ml; baseline, rejection, and resolved, respectively) and left ventricular end-diastolic volumes (133 +/- 24, 117 +/- 20, and 113 +/- 30 ml; baseline, rejection, and resolved, respectively) significantly decreased during rejection and remained decreased after resolution of rejection (rejection and resolved compared with baseline values, p less than 0.05). Right ventricular chamber stiffness (0.055 +/- 0.035, 0.085 +/- 0.057, and 0.092 +/- 0.076 mm Hg/ml; baseline, rejection, and resolution, respectively; rejection and resolved compared with baseline values, p less than 0.05) increased with rejection and remained elevated after resolution of rejection. Right ventricular peak filling rate also increased from a baseline value of 2.48 +/- 0.45 to 2.76 +/- 0.63 ml end-diastolic volumes per second with rejection (p less than 0.05). Elevation of right ventricular filling pressures, peak filling rate, and chamber stiffness with a concomitant decrease in end-diastolic volume is consistent with a restrictive/constrictive physiology. Mean arterial blood pressure and systemic vascular resistance were elevated after the resolution of rejection (compared with either rejection or baseline values, p less than 0.05) associated with a higher mean daily dose of prednisone (resolved compared with either baseline or rejection values, p less than 0.05). The control group experienced a time-dependent increase in mean and diastolic systemic arterial pressures (both comparisons, p less than 0.05) without detectable diastolic dysfunction.

CONCLUSIONS

Persistence of biventricular diastolic dysfunction may be due to an irreversible effect of rejection, although multifactorial changes in left ventricular afterload occur that may complicate serial assessment of ventricular function.

A case-control comparison of durability and cost between implanted reservoir and percutaneous catheters in cancer patients

A case-control study was performed to compare the durability and cost of implanted reservoir catheter systems with percutaneous central venous catheters. Twenty cancer patients had reservoir systems placed in 1985 for chemotherapy delivery. The control group consisted of 60 cancer patients, matched according to age, sex, and diagnosis who were part of a group of more than 700 patients with percutaneous catheters inserted during the same period. The reservoir catheters were found to function for a significantly (P less than 0.0001) longer time (495 +/- 54 days) compared to the percutaneous catheters (197 +/- 22 days). The total cost for each system was calculated by adding the charges for an average insertion (reservoir = $1738, percutaneous = $562) to the maintenance charges accumulated over the catheters' lifespan. Reservoir catheters were associated with a significantly greater total cost than percutaneous catheters ($2233 +/- 54, $1453 +/- 102, respectively) but, if the total cost was spread out over the lifespan of the catheter by dividing the total cost by duration of use, reservoir catheters can be less expensive on a per diem basis. The break point occurs at approximately 6 months. For use less than 6 months, percutaneous catheters are cheaper primarily because of their lower insertion costs, but, for longer periods, reservoir catheters become cheaper because of lower maintenance costs and because a second percutaneous catheterization would likely be necessary.

Transpelvic rectus abdominis flap reconstruction of defects following abdominal-perineal resection

Abdominal-perineal resection for advanced rectal carcinoma may leave a large defect for which complete secondary healing can be slow. In such cases, the inferiorly based rectus abdominis myocutaneous flap, passed through the pelvis into the perineum, can provide a large amount of well-vascularized tissue that may be placed in the defect to facilitate primary healing and allow a quicker recovery. Additional advantages include displacement of the bowel out of the pelvis to facilitate postoperative radiotherapy, and the ability to reconstruct vaginal wall defects. We report a series of seven patients for whom the transpelvic rectus abdominis myocutaneous flap was used to cover perineal defects following abdominal-perineal resection. Although one flap failed, all patients healed rapidly and the only lasting complication was a possibly related small upper-abdominal hernia found one year after surgery.

Absence of a relationship of size of primary colon carcinoma with metastasis and survival

This retrospective study analysed the relationship of tumor size to regional and systemic metastasis and to survival according to stage of disease. Colon cancers (391 cases) that were treated surgically at M. D. Anderson Hospital from 1955 to 1975 were reviewed. Staging of disease was based on the Astler-Coller modification of Dukes' staging classification. The mean diameters (cm +/- s.e.m.) of Dukes' B1, B2, C2 and D tumors were 4.47 +/- 0.34 (n = 46), 6.61 +/- 0.29 (n = 147), 5.39 +/- 0.23 (n = 71) and 5.78 +/- 0.24 (n = 120), respectively. The mean diameter of Dukes' B2 tumors was significantly greater than C2 (P less than 0.001) and D (P less than 0.05) tumors. Within stage B and C, size of the primary tumor showed no relationship to five year adjusted survival. Our findings suggest that colon carcinoma metastasis and survival are independent of tumor size. Because tumor burden does not account for distant disease, specific tumor cell phenotypes and biological processes are probably more important in determining metastatic disease.

Perioperative blood transfusion in patients with colon carcinoma

The effect of perioperative blood transfusion on 5- and 10-year survival following curative resection for intra-abdominal colon carcinoma was investigated retrospectively. Two hundred and seven patients with Dukes' stages A, B, and C carcinoma were divided into two groups: those who received perioperative blood transfusion and those who did not. The data indicated that survival was not altered by blood transfusion during primary surgical tumor resection. Location of tumor in intra-abdominal colon, size of tumor, units of blood received, and stage of disease also were considered in our analysis but did not change this conclusion.

Effect of serum source on protein-free diet lymphocyte blastogenesis

The influence of protein depletion on serum factors in PHA lymphocyte blastogenesis was studied in a rat model. Buffalo rats were divided randomly into two groups and fed either a protein-free (PF) diet or a regular 25% protein diet (RD). At weekly intervals, lymph node lymphocytes were cultured with PHA in either autologous or pooled 10% rat serum. For weeks 2 through 6, PHA stimulated blastogenesis of lymphocytes from rats maintained on PF diet incubated with autologous serum decreased significantly compared with RD lymphocytes cultured with RD serum. At week 4, PHA blastogenesis of PF lymphocytes cultured with RD serum was similar to that of RD lymphocytes incubated with RD serum. AT weeks 5 and 6, PHA stimulation of PF lymphocytes assayed with RD serum was depressed compared with RD lymphocytes cultured with RD. For weeks 4 through 6, blastogenesis of RD lymphocytes assayed with PF serum decreased significantly compared with RD lymphocytes incubated with RD serum. Three weeks of protein repletion of rats previously on a PF diet for 6 weeks restored PHA blastogenesis to that observed for lymphocytes from animals in the RD group. The data suggested that suppression of PHA blastogenesis of lymphocytes from rats maintained on PF diet involved a serum factor in the early stages of protein depletion and an additional defect (not serum related) in lymphocyte blastogenesis after prolonged protein depletion. In addition, this defect was corrected after a period repletion.