International Association for the Study of Lung Cancer Study of Reproducibility in Assessment of Pathologic Response in Resected Lung Cancers After Neoadjuvant Therapy

INTRODUCTION

Pathologic response has been proposed as an early clinical trial end point of survival after neoadjuvant treatment in clinical trials of NSCLC. The International Association for the Study of Lung Cancer (IASLC) published recommendations for pathologic evaluation of resected lung cancers after neoadjuvant therapy. The aim of this study was to assess pathologic response interobserver reproducibility using IASLC criteria.

METHODS

An international panel of 11 pulmonary pathologists reviewed hematoxylin and eosin-stained slides from the lung tumors of resected NSCLC from 84 patients who received neoadjuvant immune checkpoint inhibitors in six clinical trials. Pathologic response was assessed for percent viable tumor, necrosis, and stroma. For each slide, tumor bed area was measured microscopically, and pre-embedded formulas calculated unweighted and weighted major pathologic response (MPR) averages to reflect variable tumor bed proportion.

RESULTS

Unanimous agreement among pathologists for MPR was observed in 68 patients (81%), and inter-rater agreement (IRA) was 0.84 (95% confidence interval [CI]: 0.76-0.92) and 0.86 (95% CI: 0.79-0.93) for unweighted and weighted averages, respectively. Overall, unweighted and weighted methods did not reveal significant differences in the classification of MPR. The highest concordance by both methods was observed for cases with more than 95% viable tumor (IRA = 0.98, 95% CI: 0.96-1) and 0% viable tumor (IRA = 0.94, 95% CI: 0.89-0.98). The most common reasons for discrepancies included interpretations of tumor bed, presence of prominent stromal inflammation, distinction between reactive and neoplastic pneumocytes, and assessment of invasive mucinous adenocarcinoma.

CONCLUSIONS

Our study revealed excellent reliability in cases with no residual viable tumor and good reliability for MPR with the IASLC recommended less than or equal to 10% cutoff for viable tumor after neoadjuvant therapy.

Trimodality treatment versus surgery alone for esophageal cancer. A stratified analysis with minimally invasive pretreatment staging

BACKGROUND

Accurate pretreatment staging of esophageal cancer (EC) is important in the evaluation and comparison of results of different treatment modalities. Few studies using minimally invasive staging techniques for this purpose have been reported. We previously demonstrated the usefulness of the thoracoscopic/laparoscopic (Ts/Ls) technique in pretreatment staging of EC. This study was conducted to evaluate the impact of trimodality based on pretreatment Ts/Ls staging diagnosis on EC.

METHODS

A retrospective study was performed on 2 groups of EC patients. Group A (44 patients) underwent pretreatment Ts/Ls staging and had trimodality treatment. Preoperative therapy consisted of concurrent chemotherapy (5-FU + cisplatinum) and radiotherapy. Group B (33 patients) underwent surgery alone. The study focused on stratified comparison of patterns of recurrence and survival in different pretreatment surgical T, N, and TNM stage categories.

RESULTS

The 3-year disease free survival of Group A was 40.8% with a median survival of 32.0 months, it was 43.6% with a median survival of 23.6 months in Group B. The difference was not significant (p=0.87). There was no difference in recurrence pattern between the 2 groups. Patients with squamous cell carcinoma in Group A had no local recurrence during the follow-up period while those in Group B had a high local recurrence rate of 40% (p<0.005). When stratified by T factor, patients with locally advanced T stage (T3-4) in Group A had a lower distant recurrence rate than their counterpart patients in Group B (9.1 vs 38.5%, p=0.03), they had a better survival but the difference was not significant (3-year disease free survival: 41.7 vs 17.9%, p=0.14). There were no significant differences in recurrence pattern and survival in different N categories and TNM stages between 2 groups. Multivariate analysis showed that only pretreatment surgical N status was an independent prognostic factor for the whole group (p=0.02).

CONCLUSIONS

Pretreatment Ts/Ls staging can provide accurate staging information for EC patients. Trimodality treatment was successful in local control for patients with squamous cell carcinoma. It was effective in reducing distant recurrence and might prolong survival in patients with advanced T stages. Pretreatment lymph node status was the most important prognosticator regardless of treatment modality. Pretreatment pathological staging should be included in the future clinical trials on multimodality treatments in EC patients.

Pretreatment surgical lymph node staging predicts results of trimodality therapy in esophageal cancer

OBJECTIVE

Prediction of responders to induction therapy in esophageal cancer (EC) patients is important. In this study, we evaluated the role of thoracoscopic/laparoscopic (Ts/Ls) staging in prediction of treatment response and survival in EC patients with trimodality treatment.

METHODS

Retrospective study of EC patients who had undergone Ts/Ls staging and received trimodality treatment at the University of Maryland Medical Center and the Baltimore Veterans Administration Hospitals from July, 1991 to December, 1999. Preoperative therapy consisted of concurrent chemotherapy (5-FU + cisplatinum) and radiotherapy.

RESULTS

Forty-four EC patients who underwent pretreatment Ts/Ls staging during the study period were able to complete concurrent chemoradiotherapy followed by surgical resection. There were 36 men and 8 women aged 40 to 77 (median age 62). Twenty-seven (61.4%) patients were found to have lymph node metastasis by surgical staging. Fourteen patients (31.8%) had a pathologic complete response. Patients with positive lymph nodes had a lower response rate than those with negative lymph nodes (14.8% vs. 58.8%, P=0.006). Other clinicopathologic features including gender, weight loss, clinical TNM stage, surgical T stage, and histology did not correlate with treatment response. Univariate analysis showed that weight loss and treatment response were important prognostic factors for disease-free survival (P=0.01 and P=0.02, respectively). Histology, surgical N stage and surgical TNM stage appeared to be associated with prognosis (P=0.067-0.097). Multivariate analysis revealed that only surgical N status and weight loss were significant prognostic factors (P=0.05, and P=0.006, respectively).

CONCLUSIONS

Surgical Ts/Ls staging provides accurate evaluation of tumor spread in EC patients. Pretreatment N status was the single most important predictor of response to induction treatment as well as a reliable prognosticator of survival.

Thoracoscopic sympathectomy

The objective was to evaluate the safety and effectiveness of endoscopic thoracic sympathectomy (ETS) for treatment of a variety of sympathetic disorders, including hyperhidrosis, splanchnic pain, reflex sympathetic dystrophy, and Raynaud upper extremity ischemia. Sixty-three ETS procedures were performed in 34 patients at the University of Maryland Medical System between March 1992 and August 1999 (14 male patients, 20 female patients; mean age 22 years). The indications for surgery were hyperhidrosis in 26 patients, upper extremity ischemia in 3 patients, splanchnic pain and reflex sympathetic dystrophy in 2 patients each, and facial blushing in 1 patient. Preoperative symptoms resolved completely or improved significantly in 97.1% (33/34) of patients. One patient with left reflex sympathetic dystrophy had symptoms that recurred shortly after surgery. There were no major complications; one patient with hyperhidrosis reported significant compensatory hyperhidrosis. These findings suggest that ETS is a safe and effective procedure for treatment of a variety of sympathetic disorders. Its application for hyperhidrosis is very effective, and its treatment of splanchnic pain, reflex sympathetic dystrophy, and Raynaud syndrome are rewarding. With increasing experience, ETS should become established in the repertoire of the thoracic surgeon.

The role of thoracoscopic staging of esophageal cancer patients

INTRODUCTION

This study was designed to compare thoracoscopy/laparoscopy (TS/LS) staging with non-invasive clinical staging by CT and EUS for patients with esophageal carcinoma.

METHODS AND RESULTS

CT and EUS followed by TS/LS were used to stage 88 patients with EGD proven esophageal carcinoma. Thoracoscopic staging was done in 82 patients and found N1 in 11 patients. Fifty-four patients had laparoscopy which detected N1 in 21 patients. Thirty-four cases had chemoradiation followed by surgery. Esophagectomy was performed in 47 patients after thoracoscopic staging and 33 with laparoscopic staging. Of these 47 resected patients, thoracoscopic staging showed N0 in 42 patients and N1 in five patients with an accuracy of 93.6%. Laparoscopic staging detected normal celiac lymph nodes in 20 patients and diseased LN in 11 patients with an accuracy of 93.9%. Comparing with final resection pathology, the sensitivity, specificity and positive predictive value of staging for N1 disease in the chest was 62.5, 100.0 and 100.0% by TS; 75.0, 75.6, and 23.1% by CT and 0.0, 51.4 and 5.5% by EUS, respectively. For N1 disease in the abdomen it was 84.6, 100.0 and 100.0% by Ls; 0.0, 97.1 and 0.0% by CT and 22.2, 81.5 and 28.6% by EUS, respectively.

CONCLUSION

TS/LS staging of esophageal cancer patients with or without preoperative chemoradiation has a higher specificity and accuracy than CT and EUS, especially for N1 disease in the chest. It also allows individualization of preoperative radiotherapy fields.

Correction of intramyocardial hypercarbic acidosis with sodium bicarbonate

Although it has been hypothesized that exogenously administered bicarbonate can exacerbate intramyocardial acidosis and compromise contractile function, this phenomenon has not been demonstrated in an intact model in which intramyocardial pH (pH(int)), regional venous pCO2, and regional contractile function have been simultaneously monitored. In 20 anesthetized dogs, we studied the effects of intracoronary infusions of sodium bicarbonate NaHCO3 30 mEg over 15 min, on regional pH(int), (glass electrode) and regional stroke work (SW, sonomicrometry) before and after creating systemic hypercarbic acidosis by hypoventilation. During NaHCO3 administration, regional coronary venous pCO2 increased rapidly during the first minute (eucapnea; 34 +/- 7 to 55 +/- 18 mm Hg; hypercapnea: 70 +/- 15 to 98 +/- 23 mm Hg, P < 0.05 for both increases). Regional venous pH rose from 7.36 +/- .04 to 7.55 +/- .06 (P < 0.05) after the first minute of NaHCO3 infusion during eucapnea and from 7.09 +/- .09 to 7.22 +/- .09 (P < 0.05) during hypercapnea. During the first minute of NaHCO3 infusion, pH(int) declined minimally. However, during the remaining 14 min of each infusion, pH(int) increased significantly (eucapnea: 7.19 +/- 0.10 to 7.43 +/- 0.12; hypercapnea: 6.86 +/- 0.14 to 7.02 +/- 0.15, P < 0.05 for both changes). Regional SW decreased significantly during the first minute of infusion, both during eucapnea (23,400 +/- 7,400 to 18,000 +/- 6,300 ergs/cm2, P < 0.05) and hypercapnea (27,000 +/- 9,100 to 25,000 +/- 10,000 ergs/cm2, P < 0.05). The first minute of contractile dysfunction was followed by recovery and ultimately supranormal contractile function during the remainder of each bicarbonate infusion. To test the hypothesis that transient intracellular acidosis during bicarbonate infusions was underestimated by measurements of pH(int), measurements of intracellular pH using the pH-sensitive dye, BCECF, were performed in isolated guinea pig papillary muscles incubated in vitro. These measurements confirmed the presence of transient intracellular acidosis during bicarbonate infusion. In conclusion, (1) the intracoronary administration of sodium bicarbonate causes a transient depression in myocardial contractile function that is related to transient intracellular acidosis; and (2) despite exacerbating hypercarbia, sodium bicarbonate ultimately neutralizes intracellular acid and augments myocardial contractile function.

Sodium bicarbonate versus Carbicarb in canine myocardial hypercarbic acidosis

The objective of this study was to compare the in vivo effects of sodium bicarbonate (NaHCO3) and Carbicarb infusion on regional contractile performance and acid-base status in the setting of hypercarbic acidosis. Animals (N = 9) were anesthetized and paralyzed using sodium pentothal, halothane, and pancuronium bromide, and mechanically ventilated with an air-O2 mixture so that arterial PO2 was > or = 300 mm Hg. Following beta-adrenergic blockade, alveolar ventilation was gradually reduced over a 50-minute period to increase arterial PCO2 to 60 to 80 mm Hg. Each of the following solutions was then infused in consecutive order directly into the left anterior descending artery coronary artery for 15 minutes: (1) 8.4% NaHCO3 at 2 mL/min; (2) 5% sodium chloride at 2 mL/min, equivalent to NaHCO3 in osmolality; (3) 6.3% Carbicarb at 0.5 mL/min, equivalent to NaHCO3 in buffer capacity; and (4) 6.3% Carbicarb at 2 mL/min, equivalent to NaHCO3 in volume. Regional stroke work analog (ultrasonic dimension transducers), interstitial myocardial pH (Khuri electrode), coronary blood flow (doppler flow probe), and hemodynamic/metabolic variables (heart rate, blood pressure, arterial and coronary venous blood gases) were measured at 1, 5, 10, and 15 minutes during each infusion and 10 minutes after the infusion was discontinued, ie, at 25 minutes. Animals were allowed to recover for 45 minutes between interventions. Values at each time point were compared with baseline for statistical significance. Small reductions in interstitial myocardial pH (P < .05) and stroke work (P > .05) were observed within 1 minute of NaHCO3 administration. Both parameters increased significantly from baseline levels thereafter, ie, interstitial myocardial pH at 5 minutes and stroke work at 15 minutes. Infusion of Carbicarb invariably was associated with an increase (P < .05) in interstitial myocardial pH. Stroke work increased (P < .05) during low-dose Carbicarb administration, but infusion of the higher dose was accompanied by a biphasic response, ie, an increase (P < .05) from 0 to 5 minutes, followed by a gradual decrease that achieved statistical significance 10 minutes after termination of the infusion. End-diastolic length was inversely proportional to changes in stroke work, and coronary blood flow varied directly with changes in coronary venous Pco2. Myocardial O2 consumption decreased (P < .05) during Carbicarb infusion, but changes during NaHCO3 did not reach statistical significance. Our findings lend support to the hypothesis that intramyocardial pH determines myocardial function independent of CO2 production by buffer therapy.(ABSTRACT TRUNCATED AT 400 WORDS)