The impact of age on long-term survival following gastrectomy for gastric cancer

INTRODUCTION

Gastrectomy remains the primary curative treatment modality for patients with gastric cancer. Concerns exist about offering surgery with a high associated morbidity and mortality to elderly patients. The study aimed to evaluate the long-term survival of patients with gastric cancer who underwent gastrectomy comparing patients aged <70 years with patients aged ≥70 years.

METHODS

Consecutive patients who underwent gastrectomy for adenocarcinoma with curative intent between January 2000 and December 2017 at a single centre were included. Patients were stratified by age with a cut-off of 70 years used to create two cohorts. Log rank test was used to compare overall survival and Cox multivariable regression used to identify predictors of long-term survival.

RESULTS

During the study period, 959 patients underwent gastrectomy, 520 of whom (54%) were aged ≥70 years. Those aged <70 years had significantly lower American Society of Anesthesiologists grades (p<0.001) and were more likely to receive neoadjuvant chemotherapy (39% vs 21%; p<0.001). Overall complication rate (p=0.001) and 30-day postoperative mortality (p=0.007) were lower in those aged <70 years. Long-term survival (median 54 vs 73 months; p<0.001) was also favourable in the younger cohort. Following adjustment for confounding variables, age ≥70 years remained a predictor of poorer long-term survival following gastrectomy (hazard ratio 1.35, 95% confidence interval 1.09, 1.67; p=0.006).

CONCLUSIONS

Low postoperative mortality and good long-term survival were demonstrated for both age groups following gastrectomy. Age ≥70 years was, however, associated with poorer outcomes. This should be regarded as important factor when counselling patients regarding treatment options.

Comparison of multimodal analgesia with thoracic epidural after transthoracic oesophagectomy

BACKGROUND

Thoracic epidural analgesia (TEA) has been regarded as the standard of care after oesophagectomy for pain control, but has several side-effects. Multimodal (intrathecal diamorphine, paravertebral and rectus sheath catheters) analgesia (MA) may facilitate postoperative mobilization by reducing hypotensive episodes and the need for vasopressors, but uncertainty exists about whether it provides comparable analgesia. This study aimed to determine whether MA provides comparable analgesia to TEA following transthoracic oesophagectomy.

METHODS

Consecutive patients undergoing oesophagectomy for cancer between January 2015 and December 2018 were grouped according to postoperative analgesia regimen. Propensity score matching (PSM) was used to account for treatment selection bias. Pain scores at rest and on movement, graded from 0 to 10, were used. The incidence of hypotensive episodes and the requirement for vasopressors were evaluated.

RESULTS

The study included 293 patients; 142 (48.5 per cent) received TEA and 151 (51.5 per cent) MA. After PSM, 100 patients remained in each group. Mean pain scores were significantly higher at rest in the MA group (day 1: 1.5 versus 0.8 in the TEA group, P = 0.017; day 2: 1.7 versus 0.9 respectively, P = 0.014; day 3: 1.2 versus 0.6, P = 0.047). Fewer patients receiving MA had a hypotensive episode (25 per cent versus 45 per cent in the TEA group; P = 0.003) and fewer required vasopressors (36 versus 53 per cent respectively; P = 0.016). There was no significant difference in the overall complication rate (71.0 versus 61.0 per cent; P = 0.136).

CONCLUSION

MA is less effective than TEA at controlling pain, but this difference may not be clinically significant. However, fewer patients experienced hypotension or required vasopressor support with MA; this may be beneficial within an enhanced recovery programme.

Delivering esophago-gastric cancer care during the COVID-19 pandemic in the United Kingdom: a surgical perspective

BACKGROUND

The COVID-19 pandemic continues to have a significant impact on the provision of medical care. Planning to ensure there is capability to treat those that become ill with the virus has led to an almost complete moratorium on elective work. This study evaluates the impact of COVID-19 on cancer, in particular surgical intervention, in patients with esophago-gastric cancer at a high-volume tertiary center.

METHODS

All patients undergoing potential management for esophago-gastric cancer from 12 March to 22 May 2020 had their outcomes reviewed. Multi-disciplinary team (MDT) decisions, volume of cases, and outcomes following resection were evaluated.

RESULTS

Overall 191 patients were discussed by the MDT, with a 12% fall from the same period in 2019, including a fall in new referrals from 120 to 83 (P = 0.0322). The majority of patients (80%) had no deviation from the pre-COVID-19 pathway. Sixteen patients had reduced staging investigations, 4 had potential changes to their treatment only, and 10 had a deviation from both investigation and potential treatment. Only one patient had palliation rather than potentially curative treatment. Overall 19 patients underwent surgical resection. Eight patients (41%) developed complications with two (11%) graded Clavien-Dindo 3 or greater. Two patients developed COVID-19 within a month of surgery, one spending 4 weeks in critical care due to respiratory complications; both recovered. Twelve patients underwent endoscopic resections with no complications.

CONCLUSION

Care must be taken not to compromise cancer treatment and outcomes during the COVID-19 pandemic. Excellent results can be achieved through meticulous logistical planning, good communication, and maintaining high-level clinical care.

Long-term outcomes of clinical and pathological-staged T3 N3 esophageal cancer

Locally advanced esophageal cancer is associated with poor long-term survival. Pre- and post-treatment stages may differ because of neoadjuvant therapy and inaccuracies in staging. The aim of this study was to determine the outcomes of patients staged with clinical T3 N3 and pathological T3 N3 carcinoma of the esophagus and determine differences between the groups. Consecutive patients from a single unit between 2010 and 2018 were included with either clinical (cT3 N3) or pathological (pT3 N3) esophageal cancer. Outcomes were compared between patients that underwent esophagectomy with or without neoadjuvant treatment and those patients staged cT3 N3 treated non-surgically (NSR). Patients were staged using the TNM 8. This study included 156 patients, 63 patients were staged cT3 N3 initially and had NSR treatment, only three of these had radical treatment. Of the remaining 93 patients who underwent esophagectomy, 34 were initially staged as cT3 N3, 54 were found to be pT3 N3 having been staged earlier initially, and five were unchanged before and after treatment. Median overall survival (OS) for surgical cT3 N3 patients was significantly longer than pT3 N3 and NSR (median: NR vs 19 vs 8 months, P < 0.001). Twenty-seven patients with cT3 N3 had lower staging following treatment, while three had a higher stage. T3 N3 disease carries a poor prognosis. Within this cohort, cT3 N3 disease treated surgically has a high 5-year OS suggesting possible over-staging and stage migration due to neoadjuvant therapy. Those not having surgery, have a dismal prognosis. The impact of neoadjuvant treatment cannot be predicted and, current staging modalities may be inaccurate. Clinical stage should be used with caution when counseling patients regarding management and prognosis.

Impact of anastomotic leak on long-term survival in patients undergoing gastrectomy for gastric cancer

BACKGROUND

The impact of anastomotic leak (AL) on long-term outcomes after gastrectomy for gastric adenocarcinoma is poorly understood. This study determined whether AL contributes to poor overall survival.

METHODS

Consecutive patients undergoing gastrectomy in a single high-volume unit between 1997 and 2016 were evaluated. Clinicopathological characteristics, oncological and postoperative outcomes were stratified according to whether patients had no AL, non-severe AL or severe AL. Severe AL was defined as anastomotic leakage associated with Clavien-Dindo Grade III-IV complications.

RESULTS

The study included 969 patients, of whom 58 (6·0 per cent) developed AL; 15 of the 58 patients developed severe leakage. Severe AL was associated with prolonged hospital stay (median 50, 30 and 13 days for patients with severe AL, non-severe AL and no AL respectively; P < 0·001) and critical care stay (median 11, 0 and 0 days; P < 0·001). There were no significant differences between groups in number of lymph nodes harvested (median 29, 30 and 28; P = 0·528) and R1 resection rates (7, 5 and 6·5 per cent; P = 0·891). Cox multivariable regression analysis showed that severe AL was independently associated with overall survival (hazard ratio 3·96, 95 per cent c.i. 2·11 to 7·44; P < 0·001) but not recurrence-free survival. In sensitivity analysis, the results for patients who had neoadjuvant therapy then gastrectomy were similar to those for the entire cohort.

CONCLUSION

AL prolongs hospital stay and is associated with compromised long-term overall survival.

Significance of Neoadjuvant Downstaging in Carcinoma of Esophagus and Gastroesophageal Junction

Objective

To determine the impact of downstaging on outcomes in esophageal cancer, the prognostic value of clinical and pathological stage, and the difference in survival in patients with similar pathological stages with and without neoadjuvant treatment.

Background

There is little data evaluating adenocarcinoma and squamous cell carcinoma (SCC) and difference in outcomes for similar pathological stage with and without neoadjuvant treatment.

Patients and Methods

Consecutive patients with esophageal cancer from a single center were evaluated. Patients with esophageal adenocarcinoma or SCC treated with transthoracic esophagectomy and two-field lymphadenectomy were included. Comparison of outcomes with those primarily treated with surgery was made. The cTNM and ypTNM 8th edition was used.

Results

This study included 992 patients, of whom 417 received surgery alone and 575 received neoadjuvant therapy and surgery. In the neoadjuvant group, 7 (1%) had cTNM stage 2 and 418 (73%) had cTNM stage 3. Downstaging rates were similar between adenocarcinoma and SCC (54% vs. 61%, p = 0.5). Downstaging was associated with longer survival than patients with no change (adenocarcinoma, median: 82 vs. 26 months, p < 0.001; SCC, median: NR vs. 29 months, p < 0.001). On Cox regression analysis, downstaging was associated with significantly longer survival in adenocarcinoma but not in SCC. For SCC and more advanced adenocarcinoma, overall survival was significantly better when comparing like-for-like ypTN to pTN groups.

Conclusions

Pathological stage provides a better estimate of prognosis compared with clinical stage. Downstaged patients may have an improved outcome over those with comparable pathological stage who did not receive neoadjuvant treatment.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08358-0) contains supplementary material, which is available to authorized users.

Anastomotic Leak Does Not Impact on Long-Term Outcomes in Esophageal Cancer Patients

Background

Esophagectomy is a technically demanding procedure associated with high levels of morbidity. Anastomotic leak (AL) is a common complication with potentially major ramifications for patients. It has also been associated with poorer long-term overall survival (OS) and disease recurrence.

Objective

The aim of this study was to determine whether AL contributes to poor OS and recurrence-free survival (RFS) for patients with esophageal cancer.

Methods

Consecutive patients undergoing a two-stage, two-field transthoracic esophagectomy from a single high-volume unit between 1997 and 2016 were evaluated. Clinicopathologic characteristics, along with oncological and postoperative outcomes, were stratified by no AL versus non-severe leak (NSL) versus severe esophageal AL (SEAL). SEAL was defined as ALs associated with Clavien–Dindo grade III/IV complications.

Results

This study included 1063 patients, of whom 8% (87/1063) developed AL; 45% of those who developed AL were SEALs (39/87). SEAL was associated with a prolonged critical care stay (median 8 vs. 3 vs. 2 days; p < 0.001) and prolonged hospital stay (median 43 vs. 27 vs. 15 days; p < 0.001) compared with NSL or no AL. There were no significant differences in number of lymph nodes harvested and rates of R1 resection between groups. OS and RFS were not affected by either NSL or SEAL, and Cox multivariate regression showed NSL and SEAL were not independently associated with OS and RFS. Sensitivity analysis in patients receiving neoadjuvant therapy followed by esophagectomy demonstrated similar findings.

Conclusion

These results demonstrate that AL leads to prolonged critical care and in-hospital length of stay; however, contrary to previous reports, our results do not compromise long-term outcomes and are unlikely to have a detrimental oncological impact.

Impact of trainee involvement in esophagectomy on clinical outcomes: a narrative systematic review of the literature

Changes in the structure of surgical training have affected trainees' operative experience. Performing an esophagectomy is being increasingly viewed as a complex technical skill attained after completion of the routine training pathway. This systematic review aimed to identify all studies analyzing the impact of trainee involvement in esophagectomy on clinical outcomes. A search of the major reference databases (Cochrane Library, MEDLINE, EMBASE) was performed with no time limits up to the date of the search (November 2017). Results were screened in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and study quality assessed using the MINORS (Methodological Index for Non-Randomized Studies) criteria. Four studies that included a total of 42 trainees and 16 consultants were identified, which assessed trainee involvement in open esophagogastric resectional surgery. A total of 1109 patients underwent upper gastrointestinal procedures, of whom 904 patients underwent an esophagectomy. Preoperative characteristics, histology, neoadjuvant treatment, and overall length of hospital stay were comparable between groups. One study found higher rates of anastomotic leaks in procedures primarily performed by trainees as compared to consultants (P < 0.01)-this did not affect overall morbidity or survival; however, overall anastomotic leak rates from the published data were 10.4% (trainee) versus 6.3% (trainer) (P = 0.10). A meta-analysis could not be performed due to the heterogeneity of data. The median MINORS score for the included studies was 13 (range 11-15). This study demonstrates that training can be achieved with excellent results in high-volume centers. This has important implications on the consent process and training delivered, as patients wish to be aware of the risks involved with surgery and can be reassured that appropriately supervised trainee involvement will not adversely affect outcomes.

Trainee performance in radical gastrectomy and its effect on outcomes

Background

This study aimed to determine whether trainee involvement in D2 gastrectomies was associated with adverse outcomes.

Methods

Data from a prospectively created database of consecutive patients undergoing open D2 total (TG) or subtotal (STG) gastrectomy with curative intent between January 2009 and January 2014 were reviewed. Short‐ and long‐term clinical outcomes were compared in patients operated on by consultants and those treated by trainees under consultant supervision.

Results

A total of 272 D2 open gastrectomies were performed, 123 (45·2 per cent) by trainees. There was no significant difference between consultants and trainees in median duration of surgery (TG: 240 (range 102–505) versus 240 (170–375) min respectively, P = 0·452; STG: 225 (150–580) versus 212 (125–380) min, P = 0·192), number of resected nodes (TG: 30 (13–101) versus 30 (11–102), P = 0·681; STG: 26 (5–103) versus 25 (1–63), P = 0·171), length of hospital stay (TG: 15 (7–78) versus 15 (8–65) days, P = 0·981; STG: 10 (6–197) versus 14 (7–85) days, P = 0·242), overall morbidity (TG: 44 versus 49 per cent, P = 0·314; STG: 34 versus 25 per cent, P = 0·113) or mortality (TG: 4 versus 2 per cent; P = 0·293). No difference in predicted 5‐year overall survival was noted between the two cohorts (TG: 68 per cent for consultants versus 77 per cent for trainees, P = 0·254; STG: 70 versus 75 per cent respectively, P = 0·512). The trainee cohort had lower median blood loss for both TG (360 (range 90–1200) ml versus 600 (70–2350) ml for consultants; P = 0·042) and STG (235 (50–1000) versus 360 (50–3000) ml respectively; P = 0·053).

Conclusion

Clinical outcomes were not compromised by supervised trainee involvement in D2 open gastrectomy.

Cardiopulmonary fitness before and after neoadjuvant chemotherapy in patients with oesophagogastric cancer

BACKGROUND

Neoadjuvant chemotherapy may have a detrimental impact on cardiorespiratory reserve. Determination of oxygen uptake at the anaerobic threshold by cardiopulmonary exercise testing (CPET) provides an objective measure of cardiorespiratory reserve. Anaerobic threshold can be used to predict perioperative risk. A low anaerobic threshold is associated with increased morbidity after oesophagogastrectomy. The aim of this study was to establish whether neoadjuvant chemotherapy has an adverse effect on fitness, and whether there is recovery of fitness before surgery for oesophageal and gastric adenocarcinoma.

METHODS

CPET was completed before, immediately after (week 0), and at 2 and 4 weeks after neoadjuvant chemotherapy. The ventilatory anaerobic threshold and peak oxygen uptake (Vo₂ peak) were used as objective, reproducible measures of cardiorespiratory reserve. Anaerobic threshold and Vo₂ peak were compared before and after neoadjuvant chemotherapy, and at the three time intervals.

RESULTS

Some 31 patients were recruited. The mean anaerobic threshold was lower following neoadjuvant treatment: 15·3 ml per kg per min before chemotherapy versus 11·8, 12·1 and 12·6 ml per kg per min at week 0, 2 and 4 respectively (P < 0·010). Measurements were also significantly different at each time point (P < 0·010). The same pattern was noted for Vo₂ peak between values before chemotherapy (21·7 ml per kg per min) and at weeks 0, 2 and 4 (17·5, 18·6 and 19·3 ml per kg per min respectively) (P < 0·010). The reduction in anaerobic threshold and Vo₂ peak did not improve during the time between completion of neoadjuvant chemotherapy and surgery.

CONCLUSION

There was a decrease in cardiorespiratory reserve immediately after neoadjuvant chemotherapy that was sustained up to the point of surgery at 4 weeks after chemotherapy.

Cardiopulmonary fitness before and after neoadjuvant chemotherapy in patients with oesophagogastric cancer

Background

Neoadjuvant chemotherapy may have a detrimental impact on cardiorespiratory reserve. Determination of oxygen uptake at the anaerobic threshold by cardiopulmonary exercise testing (CPET) provides an objective measure of cardiorespiratory reserve. Anaerobic threshold can be used to predict perioperative risk. A low anaerobic threshold is associated with increased morbidity after oesophagogastrectomy. The aim of this study was to establish whether neoadjuvant chemotherapy has an adverse effect on fitness, and whether there is recovery of fitness before surgery for oesophageal and gastric adenocarcinoma.

Methods

CPET was completed before, immediately after (week 0), and at 2 and 4 weeks after neoadjuvant chemotherapy. The ventilatory anaerobic threshold and peak oxygen uptake (Vo2 peak) were used as objective, reproducible measures of cardiorespiratory reserve. Anaerobic threshold and Vo2 peak were compared before and after neoadjuvant chemotherapy, and at the three time intervals.

Results

Some 31 patients were recruited. The mean anaerobic threshold was lower following neoadjuvant treatment: 15·3 ml per kg per min before chemotherapy versus 11·8, 12·1 and 12·6 ml per kg per min at week 0, 2 and 4 respectively (P &lt; 0·010). Measurements were also significantly different at each time point (P &lt; 0·010). The same pattern was noted for Vo2 peak between values before chemotherapy (21·7 ml per kg per min) and at weeks 0, 2 and 4 (17·5, 18·6 and 19·3 ml per kg per min respectively) (P &lt; 0·010). The reduction in anaerobic threshold and Vo2 peak did not improve during the time between completion of neoadjuvant chemotherapy and surgery.

Conclusion

There was a decrease in cardiorespiratory reserve immediately after neoadjuvant chemotherapy that was sustained up to the point of surgery at 4 weeks after chemotherapy.

Clinical outcomes and benefits for staging of surgical lymph node mapping after esophagectomy

Dissection of lymph nodes (LN) immediately after esophagectomy is utilized by some surgeons to aid determination of LN stations involved in esophageal cancer. Some suggest that this increases LN yield and gives information regarding the pattern of lymphatic spread, others feel that this may compromise a circumferential resection margin (CRM) assessment. The aim of this study is to evaluate the effect of ex vivo dissection on the assessment of the CRM and the pattern of lymph node dissemination in patients with adenocarcinoma of the esophagus and gastroesophageal junction (GEJ) undergoing radical surgery after neoadjuvant chemotherapy and their prognostic impact. Data from consecutive patients with potentially curable adenocarcinoma of the distal esophagus and GEJ who received neoadjuvant treatment followed by surgery were analyzed. Clinical and pathological findings were reviewed and LN burden and location correlated with clinical outcome. Pathology specimens were dissected into individual LN groups 'ex-vivo' by the surgeon. A total of 301 patients were included: 295 had a radical proximal and distal resection margin however in 62(20.6%) CRM could not be assessed. A median of 33(10-77) nodes were recovered. A 117(38.9%) patients were ypN0 while 184(61.1%) were LN positive (ypN1-N3). LN stations close to the tumor were most frequently involved. Twenty-seven (14.7%) patients had only thoracic stations involved, 48(26.1%) only abdominal stations and 109 (59.2%) had both. Median survival for yN0 patients was 171 months compared to 24 months for those LN positive (P< 0.001). Multivariate analyses identified ypT-category, ypN-category, male gender, and nonradical resection (proximal or distal) margin as significant prognostic factors. Surgical dissection of nodes after esophagectomy enables accurate LN assessment, but may compromise CRM assessment in up to 20% of cases. It also provides valuable information regarding the pattern of nodal spread.

Prognostic impact of extracapsular lymph node involvement after neoadjuvant therapy and oesophagectomy

BACKGROUND

The significance of extracapsular lymph node involvement (LNI) is unclear in patients with oesophageal cancer who have undergone neoadjuvant treatment followed by oesophagectomy. The aim of this study was to assess the incidence and prognostic significance of extracapsular LNI in a large multicentre series of consecutive patients with oesophageal cancer treated by neoadjuvant chemotherapy or chemoradiotherapy and surgery.

METHODS

Data from a consecutive series of patients treated at two European centres were analysed. All patients with squamous cell carcinoma or adenocarcinoma of the oesophagus or gastro-oesophageal junction, who received neoadjuvant chemotherapy or chemoradiation followed by transthoracic oesophagectomy and two-field lymphadenectomy with curative intent, were included.

RESULTS

Between January 2000 and September 2013, 704 patients underwent oesophagectomy after neoadjuvant therapy. A median of 28 (range 5-77) nodes per patient was recovered. Some 347 patients (49·3 per cent) had no LNI (ypN0). Of the remaining 357 patients (50·7 per cent) with LNI (ypN1-3), extracapsular LNI was found in 190 (53·2 per cent). Five-year overall survival rates were 62·7 per cent for patients with N0 disease, 44·9 per cent for patients without extracapsular spread and 14·0 per cent where extracapsular LNI was identified (P < 0·001). Multivariable analyses demonstrated the presence of extracapsular LNI as an independent prognostic factor.

CONCLUSION

The presence of extracapsular LNI after neoadjuvant therapy carries a poor prognosis.

The impact of neoadjuvant chemotherapy on cardiopulmonary physical fitness in gastro-oesophageal adenocarcinoma

Introduction Operable oesophagogastric adenocarcinoma management in the UK includes three cycles of neoadjuvant chemotherapy (NAC) followed by resection. Determination of oxygen uptake at the anaerobic threshold (AT) with cardiopulmonary exercise testing (CPET) is used to objectively measure cardiorespiratory reserve. Oxygen uptake at AT predicts perioperative risk, with low values associated with increased morbidity. Previous studies indicate NAC may have a detrimental impact on cardiorespiratory reserve. Methods CPET was completed by 30 patients before and after a standardised NAC protocol. The ventilatory AT was determined using the V-slope method, and the peak oxygen uptake and ventilatory equivalents for carbon dioxide measured. Median AT before and after chemotherapy was compared using a paired Student's t-test. Results Median oxygen uptake at AT pre- and post-NAC was 13.9±3.1 ml/kg/min and 11.5±2.0 ml/kg/min, respectively. The mean decrease was 2.4 ml/kg/min (95% confidence interval [CI] 1.3-3.85; p<0.001). Median peak oxygen delivery also decreased by 2.17 ml/kg/min (95% CI 1.02-3.84; p=0.001) after NAC. Ventilatory equivalents were unchanged. Conclusions This reduction in AT objectively quantifies a decrease in cardiorespiratory reserve after NAC. Patients with lower cardiorespiratory reserve have increased postoperative morbidity and mortality. Preventing this decrease in cardiorespiratory reserve during chemotherapy, or optimising the timing of surgical resection after recovery of AT, may allow perioperative risk-reduction.

The impact of neoadjuvant chemotherapy on cardiopulmonary physical fitness in gastro-oesophageal adenocarcinoma

Introduction Operable oesophagogastric adenocarcinoma management in the UK includes three cycles of neoadjuvant chemotherapy (NAC) followed by resection. Determination of oxygen uptake at the anaerobic threshold (AT) with cardiopulmonary exercise testing (CPET) is used to objectively measure cardiorespiratory reserve. Oxygen uptake at AT predicts perioperative risk, with low values associated with increased morbidity. Previous studies indicate NAC may have a detrimental impact on cardiorespiratory reserve. Methods CPET was completed by 30 patients before and after a standardised NAC protocol. The ventilatory AT was determined using the V-slope method, and the peak oxygen uptake and ventilatory equivalents for carbon dioxide measured. Median AT before and after chemotherapy was compared using a paired Student's t-test. Results Median oxygen uptake at AT pre- and post-NAC was 13.9±3.1 ml/kg/min and 11.5±2.0 ml/kg/min, respectively. The mean decrease was 2.4 ml/kg/min (95% confidence interval [CI] 1.3-3.85; p<0.001). Median peak oxygen delivery also decreased by 2.17 ml/kg/min (95% CI 1.02-3.84; p=0.001) after NAC. Ventilatory equivalents were unchanged. Conclusions This reduction in AT objectively quantifies a decrease in cardiorespiratory reserve after NAC. Patients with lower cardiorespiratory reserve have increased postoperative morbidity and mortality. Preventing this decrease in cardiorespiratory reserve during chemotherapy, or optimising the timing of surgical resection after recovery of AT, may allow perioperative risk-reduction.

The presence of lymphovascular and perineural infiltration after neoadjuvant therapy and oesophagectomy identifies patients at high risk for recurrence

Background:

In patients treated for oesophageal cancer the importance of lymphovascular and perineural invasion (PNI) after neoadjuvant therapy has yet to be established. The aim of this study was to assess the incidence and prognostic significance of these factors in a consecutive series of patients with cancer of the oesophagus or gastro-oesophageal junction (GOJ) who underwent neoadjuvant therapy followed by oesophagectomy.

Methods:

Clinical and pathology results from patients with potentially curable adenocarcinoma, or squamous cell carcinoma of the oesophagus or GOJ were reviewed. Patients were treated with neoadjuvant chemotherapy or chemoradiation followed by transthoracic oesophagectomy and two-field lymphadenectomy. The presence of venous invasion (VI), lymph vessel invasion (LI) and perineural invasion (PNI) were correlated with clinical outcomes.

Results:

A total of 396 patients underwent oesophagectomy after neoadjuvant therapy for oesophageal cancer. Venous invasion was identified in 150 (38%) of patients, LI in 203 (51%) patients and PNI in 204 (52%) patients. In all, 123 (31%) patients had no evidence of either VI, LI or PNI. A total of 96 (24%) had a combination of two factors and 94 (24%) had all three factors. The presence of VI, LI and PNI was significantly related to tumour stage (P=0.001). Median overall survival was 170.8 months when all three factors were absent, 44.0 months when one factor was present, 27.1 months when two factors were present and 16.0 months when all were present. Multivariate analyses revealed VI, LI and PNI or a combination of these factors were independent predictors of prognosis.

Conclusions:

In oesophageal cancer patients treated with neoadjuvant therapy followed by oesophagectomy the presence of VI, LI and PNI has an important prognostic impact and may identify patients at high risk of recurrence who would benefit from adjuvant therapies.

Mineral distribution in rat skeletons after exposure to a microgravity model

Exposure to space flight models induces changes in the distribution of bone mineral in the human skeleton that has the features of a gravitational gradient. Regional bone mineral measurements with dual energy x-ray absorptiometry (DEXA) in male adults exposed to head-down tilt bed rest for 30 days show non-significant decrements in the pelvis and legs with 10% increases in the head region. Horizontal bed rest for 17 weeks reveals losses of bone mineral ranging from 2.2 to 10.4% from the lumbar spine to the calcaneus and an increase of 3.4% in the skull. Investigation of this phenomena would be most definitively carried out in an animal model. One candidate is the flight simulation model in the rat which removes body weight from the hind limbs and induces a cephalad fluid shift by suspending the animal by the tail. Weanling rats exposed to this model showed bone mineral to be lower in the hind limbs and higher in the skull after 3 weeks. These findings are similar in older 200 g animals after 2 weeks tail suspension. The purpose of this study was to determine the effect of age on the distribution of skeletal mineral in this model.

Effect of excess dietary salt on calcium metabolism and bone mineral in a spaceflight rat model

High levels of salt promote urinary calcium (UCa) loss and have the potential to cause bone mineral deficits if intestinal Ca absorption does not compensate for these losses. To determine the effect of excess dietary salt on the osteopenia that follows skeletal unloading, we used a spaceflight model that unloads the hindlimbs of 200-g rats by tail suspension (S). Rats were studied for 2 wk on diets containing high salt (4 and 8%) and normal calcium (0.45%) and for 4 wk on diets containing 8% salt (HiNa) and 0.2% C (LoCa). Final body weights were 9-11% lower in S than in control rats (C) in both experiments, reflecting lower growth rates in S than in C during pair feeding. UCa represented 12% of dietary Ca on HiNa diets and was twofold higher in S than in C transiently during unloading. Net intestinal Ca absorption was consistently 11-18% lower in S than in C. Serum 1,25-dihydroxyvitamin D was unaffected by either LoCa or HiNa diets in S but was increased by LoCa and HiNa diets in C. Despite depressed intestinal Ca absorption in S and a sluggish response of the Ca endocrine system to HiNa diets, UCa loss did not appear to affect the osteopenia induced by unloading. Although any deficit in bone mineral content from HiNa diets may have been too small to detect or the duration of the study too short to manifest, there were clear differences in Ca metabolism from control levels in the response of the spaceflight model to HiNa diets, indicated by depression of intestinal Ca absorption and its regulatory hormone.

Effects of fish oil supplementation on acute ischemic brain injury in the rat

We studied the effects of long-term fish oil (FO) dietary supplementation on brain edema, polymorphonuclear neutrophil (PMN) infiltration, and infarct size in a rat stroke model. Rats were given regular rat chow with or without FO supplement (20% of total calories) for 7 weeks. Body weight did not differ between the two groups. In the FO group, an increase in eicosapentaenoic acid and a decrease in arachidonic acid content in hepatic phospholipids were significant in the phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine but not in the phosphoinositol fraction. Platelet activity reflected by serum thromboxane B2 levels was reduced in the FO group. Postischemic brain edema and PMN infiltration were not different between the two groups. The infarct volume was significantly greater in the FO group (controls: 96 +/- 7 mm3, n = 49; FO group: 124 +/- 6 mm3, n = 53; p = 0.0036). The greater ischemic brain injury in the FO-supplemented animals is probably related to the intraischemic hyperglycemia, which was worse in the FO group than in the control group (controls: 265 +/- 19 mg/dl, n = 14; FO group: 340 +/- 18 mg/dl, n = 16; p = 0.0079).

Effects of acute ethanol administration on polyphosphoinositide turnover and levels of inositol 1,4,5-trisphosphate in mouse cerebrum and cerebellum

Although ethanol is known for its central depressant action, its effect on the polyphosphoinositide (poly-PI) signal transduction activity in brain has not been examined in detail. In this study, C57Bl/6J mice were injected intracerebrally with [3H]inositol, and poly-PI turnover in brain was assessed by determining the levels of labeled inositol monophosphates (IP1) accumulated after intraperitoneal injection of LiCl (6 meq/kg body weight) 4 hr before killing. Using this experimental protocol, acute ethanol administration (by gavage) resulted in time- and dose-dependent decreases in the levels of labeled IP1 in both cerebrum and cerebellum as compared with controls. The ethanol-induced decrease in labeled IP1 correlated well with the decrease in levels of inositol 1,4,5-triphosphate (as measured by the radioreceptor assay) and the increase in blood ethanol concentration. Despite a 4-fold higher accumulation of labeled IP1 in the cerebrum compared with the cerebellum, there were no major differences in the steady-state levels of inositol 1,4,5-triphosphate (based on tissue weight) in either brain region. Intraperitoneal injection of atropine (50 mg/kg) (a muscarinic cholinergic receptor antagonist) to the lithium-treated mice resulted in a 34% decrease in labeled IP1 as compared with controls. This result suggests that a substantial proportion of the signals transduced were due to activation of the muscarinic cholinergic receptor. Administration of ethanol (5 g/kg) to the atropine-treated mice resulted in a further decrease in labeled IP1 and longer sleep time as compared with those given ethanol alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of chronic ethanol administration on poly-phosphoinositide metabolism in the mouse brain: variance with age

Using a procedure in which poly-phosphoinositides (poly-PI) in C57Bl mouse brain were labeled with [32P]Pi or [32P]ATP, the effects of chronic ethanol administration and age on metabolism of these anionic phospholipids were examined. Within 4 h after intracerebral injection, both labeled precursors were effectively incorporated into membrane phospholipids with high proportions of labeling among phosphatidylcholine, phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate. With few exceptions, the phospholipid labeling patterns in different brain regions, e.g. cortex, hippocampus and hypothalamus, were similar. However, when the brain homogenate was subjected to differential and sucrose-Ficoll gradient centrifugation, different phospholipid labeling patterns were observed in the subcellular membrane fractions. Young adult mice given an ethanol (5% w/v) liquid diet for 2 months showed an increase in the levels of labeled phosphatidylinositol 4-phosphate, phosphatidylinositol 4,5-bisphosphate and phosphatidylserine in the cortex and hippocampus as compared to the pair-fed controls, but these changes were not observed in the hypothalamus. In another study, 12- and 26-month-old mice were administered either an ethanol (8 g/kg in two doses daily) or a control diet by gavage for 3 weeks. The 12-month-old group given the ethanol diet showed an increase in labeled poly-PI which was found largely in the synaptosomal fraction. Surprisingly, the 26-month-old mice given the same ethanol paradigm showed a decrease in labeled poly-PI. Consistent with our previous observations, the 26-month-old mice showed a higher proportion of labeled poly-PI in the synaptosomal fraction as compared to the younger age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Lithium effects on inositol phospholipids and inositol phosphates: evaluation of an in vivo model for assessing polyphosphoinositide turnover in brain

Administration of lithium chloride to rats injected intracerebrally with [3H]inositol led to time- and dose-dependent increases in levels of labeled inositol monophosphates in brain. Quantitative analysis of the inositol phosphates by ion chromatography revealed 37- and 20-fold increases in the mass of myo-inositol 1-phosphate and 4-phosphate, respectively, at 4 h intraperitoneal after injections of 6 mEq/kg of lithium chloride. Albeit to a much lesser extent, lithium administration also resulted in an increase in the level of myo-inositol, 1,4-bisphosphate in brain. The lithium-induced increase in content of labeled inositol monophosphates was marked by a concomitant decrease in content of labeled inositol, and after injections of high doses of lithium, e.g., 10 mEq/kg, this was followed by a general decrease in labeling of the inositol phospholipids. In general, animals injected with [3H]inositol but not lithium did not reveal obvious differences in labeling of inositol monophosphates on stimulation by mecamylamine or pilocarpine. However, when animals were injected with [3H]inositol and then lithium, there were large increases in the levels of labeled inositol monophosphates on administration of these compounds. Administration of atropine to the lithium-treated mice led to a partial reduction in the amount of labeled inositol monophosphates accumulated due to the administration of lithium alone. Furthermore, atropine was able to block the pilocarpine-induced increase in level of labeled inositol monophosphates. These results demonstrate the suitable use of the radiotracer technique together with lithium administration for assessing the effects of drugs and receptor agonists on the signaling system involving polyphosphoinositide turnover in brain.

Effects of cholesterol and fat modification of self-selected diets on serum lipids and their specific fatty acids in normocholesterolemic and hypercholesterolemic humans

A 6-month crossover diet plan was employed to study the effects on human serum lipids of adding margarine or butter to otherwise self-selected diets that included two eggs daily. Two groups of subjects were studied: 51 free-living normocholesterolemic and 20 hypercholesterolemic (greater than 240 mg dl). Four-day diet records in each interval showed that subjects ate about 16% of total dietary fat as either butter or margarine. Blood samples taken every 6 weeks showed variable mean serum total cholesterol (SCHOL), high-density-lipoprotein cholesterol (HDL-C), and serum triglycerides (STG). The normocholesterolemic subjects who ate butter first had by 24 weeks mean SCHOL values equal to their entry values; those who ate margarine first had increased SCHOL values throughout the study. By the end of the study, the hypercholesterolemic subjects showed either no change or a slight decrease in both SCHOL and HDL-C values. Specific fatty acids were distributed differently in the serum fractions of triacylglycerol (TGFA), cholesteryl esters (CEFA), and phospholipids (PLFA). These distributions remained constant in both normocholesterolemic and hypercholesterolemic subjects regardless of the type and amount of fat consumed.

Brief chronic effects of lithium administration on rat brain phosphoinositides and phospholipids

Lithium is known to exert its biochemical action on cells and tissues by inhibiting the enzymic conversion of inositol monophosphates to inositol. However, it is not clear whether this inhibitory action may lead to changes in the de novo biosynthesis of phosphatidylinositol and its phosphorylated derivatives. This biosynthetic scheme may have an important bearing with regard to the receptor-mediated signal transduction mechanism involving hydrolysis of polyphosphoinositides and release of inositol trisphosphate as second messenger for mobilization of intracellular calcium. In this study, the effects of brief chronic lithium administration on metabolism of brain phosphoinositides and other phospholipids were examined using the radiotracer technique with 32Pi as precursor. Sprague Dawley rats that were treated with lithium (3-4 meq/kg body wt) twice daily for 2-6 days consistently indicated an increase in the labeling of phosphatidylinositol 4,5-bisphosphates and a decrease in labeling of phosphatidylinositols and phosphatidylethanolamines. These phospholipid changes were found in both cortex and hippocampus and appeared to occur primarily in the synaptosomal fraction. Although the extent of the phospholipid changes could vary depending on both duration and dose levels of the lithium administered, these results demonstrated subtle effects of lithium on depressing the biosynthesis of phosphatidylinositol as well as phosphatidylethanolamine but perhaps a compensative increase in the synthesis of the phosphatidylinositol 4,5-bisphosphates.

Metabolism of phosphatidylinositol in plasma membranes and synaptosomes of rat cerebral cortex: a comparison between endogenous vs exogenous substrate pools

The metabolism of phosphatidylinositols (PI) labeled with [14C]arachidonic acid within plasma membranes or synaptosomes was compared to the metabolism of PI prelabeled with [14C]arachidonic acid and added exogenously to the same membranes. Incubation of membranes containing the endogenously-labeled PI pool in the presence of Ca2+ resulted in the release of labeled arachidonic acid, as well as a small amount of labeled diacylglycerol. Labeled arachidonic acid was effectively reutilized and returned to the membrane phospholipids in the presence of adenosine triphosphate (ATP), CoA, and lysoPI. Although Ca2+ promoted the release of labeled diacylglycerol from prelabeled plasma membranes, this amount was only 17% of the maximal release, i.e., release in the presence of deoxycholate and Ca2+. This latter condition is known to fully activate the PI-phospholipase C, and incubation of prelabeled plasma membranes resulted in a six-fold increase in labeled diacylglycerols. On the other hand, when exogenously labeled PI were incubated with plasma membranes in the presence of Ca2+, the labeled diacylglycerols released were 59% of that compared to the fully activated condition. The phospholipase C action was calcium-dependent, regardless of whether exogenous or endogenous substrates were used in the incubation. In contrast to plasma membranes, intact synaptosomes had limited ability to metabolize exogenous PI even in the presence of Ca2+, although the activity of phospholipase C was similar to that in the plasma membranes when assayed in the presence of deoxycholate and Ca2+. These results suggest that discrete pools of PI are present in plasma membranes, and that the pool associated with the acyltransferase is apparently not readily accessible to hydrolysis by phospholipase C.