Lung transplantation for lung cancer: A systematic review of the literature

BACKGROUND

Lung transplant (LTx) is an accepted treatment for end-stage pulmonary failure. A small proportion of explanted lungs harbor incidentally identified nonsmall cell lung cancers (NSCLC). We review the literature on studies assessing LTx patients found to have NSCLC lung cancer in their explanted lungs, and perform a pooled analysis of outcomes.

METHODS

MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched. We included studies assessing outcomes of patients with incidentally identified NSCLC following LTx, or following LTx for diffuse lepidic adenocarcinoma as a primary indication.

RESULTS

A total of 1404 articles were reviewed. 17 eligible studies were identified: 14 studies on incidental NSCLC (N = 169), 4 on diffuse lepidic adenocarcinoma (N = 70). Overall survival (OS) for patients with incidentally identified lung cancer at 1-year, 3-year, and 5-year was 60.8% (95%CI 43.7%-77.9%, I2 =81.8%), 25.5% (95%CI 1.6%-49.5%, I2 =93.6%), and 23.0% (95%CI 2.0%-44.0%, I2 =92.0%) respectively. When restricted to those with earlier stage disease, those with stage I or II NSCLC had better 1-year, 3-year, and 5-year OS at 72.7% (95%CI 57.2%-88.2%, I2 =67.3%), 41.6% (95%CI 14.0%-69.1%, I2 =89.1%), and 34.5% (95%CI 8.1%-61.0%, I2 =89.8%), respectively. A sensitivity analysis limited to stage I showed 1-year, 3-year, and 5-year survival of 73.0% (95%CI 56.3%-89.7%), 40.4% (95%CI 110.3%-70.6%), and 35.4% (95%CI 6.2%-64.5%), respectively. The 4 studies on diffuse lepidic adenocarcinoma were too heterogeneous for pooled analysis.

CONCLUSIONS

We present a review and pooled analysis examining survival following LTx with incidentally identified NSCLC. Patients with earlier stage incidentally explanted NSCLC had better survival outcomes. OS in the stage I population approximates that of LTx without incidental NSCLC.

Everolimus Use in Lung Transplant Recipients

BACKGROUND

Most lung transplantation centers prefer triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil, and corticosteroids. However, to prevent complications and comorbidities caused by tacrolimus, replacing the drug with everolimus has been considered.

METHODS

This is a retrospective observational study investigating everolimus switch for different reasons. The population was divided into 3 groups: chronic lung allograft dysfunction (CLAD), kidney impairment, and malignant neoplasm groups. We investigated whether we achieved the goal of the switch and the frequency of rejection, cytomegalovirus and fungal infections, and everolimus adverse effects.

RESULTS

Nineteen patients received everolimus therapy, and 5 of these were for CLAD, 7 for tacrolimus nephrotoxicity, and 7 for explant/de novo malignant neoplasm. The patients were followed up for a mean (SD) of 30 (16.7) months under the therapy. The number of acute cellular rejection, cytomegalovirus infection, and aspergillosis infection cases before switch were 7, 13, and 2, respectively, and 7, 2, and 3 after that. The mean values of creatinine and estimated glomerular filtration rate of the whole population after the switch improved with no statistical significance, whereas it was significant in tacrolimus nephrotoxicity group. Three patients in the CLAD group remained stable after switching, whereas 2 progressed. Only 1 of the 7 patients with malignant neoplasms had a recurrence during 31.1 (16.5) months of median follow-up. Eleven cases of everolimus adverse effects occurred in 9 patients (47.3%), with 2 (10.5%) withdrawal events. Kidney impairment (P = .02) and age (P = .05) stood out as significant risk factors for drug adverse effects.

CONCLUSIONS

After lung transplant, everolimus can be a safe alternative for immunosuppression with acceptable adverse effects.

Explanted malignancies after lung transplantation: the University of Michigan experience

The management of patients with an explanted malignancy after lung transplantation is not well understood. We reviewed our institutional experience and outcomes at a single academic medical centre between December 1997 and April 2021 for patients with malignancies of all histologic types identified on explant pathology. Primary lung cancers were reclassified using the 8th Edition TNM staging and the 2021 World Health Organization histologic classification of lung cancers. Of the 733 patients undergoing lung transplantation, 15 (2.05%) were found to have malignancy on the explanted lungs, including 6 (0.82%) primary lung cancers. Four patients were found to have early-stage lung cancers, while 2 patients had advanced-stage IV disease. Survival ranged from 0 to 109 months for the entire cohort with median 23.2 [49.9] months in those with primary lung cancers. There were 2 recurrences following explanted stage I (15 months) and stage IV (53 months) diseases. Other explant pathologies included carcinoid tumourlets in 6 patients, lymphoma in 2 and metastatic leiomyosarcoma in 1. In conclusion, explanted lung malignancies are an infrequent but significant finding on explant pathology. Further data are needed to better characterize and stratify this patient cohort.

Incidentally Detected Malignancies in Lung Transplant Explants

Active malignancy diagnosed within 5 years is an absolute contraindication for lung transplantation. In this study, we evaluated the rate of incidental malignancies detected in explanted lungs at our institution and assessed the posttransplant survival in patients with nonsmall cell lung cancer (NSCLC).

Methods

A retrospective chart review of lung transplant recipients at our institution from February 1999 to June 2017 was conducted. A literature review was performed to evaluate the prevalence and survival outcomes in patients with unexpected malignancies.

Results

From 407 patients who underwent lung transplantation, 9 (2.2%) were discovered to have malignant neoplasms. There were 3 cases of adenocarcinoma, 3 cases of adenocarcinoma in situ, 2 cases of squamous cell carcinoma, and 1 case of metastatic renal cell carcinoma. An extensive literature review found 12 case reports or case series reporting malignancy discovered at the time of lung transplantation. The overall prevalence of incidental neoplasms among 6746 recipients is around 1.5% (n = 103). The most common neoplasms discovered included adenocarcinoma (n = 56, 54%) and squamous cell carcinoma (n = 29, 28%). The overall 3-year survival was 54.4% for patients with localized NSCLC compared to 5.7% for those with nonlocalized disease.

Conclusions

Unidentified malignancies occur despite aggressive radiographic surveillance with poor posttransplant outcomes in patients with advanced malignancy. Malignancy-related radiographic findings may be missed pretransplant secondary to architectural distortion of lung parenchyma related to end-stage lung disease or because of the critical timing of surgery when donor lungs are available.

Patterns of Recurrence and Overall Survival in Incidental Lung Cancer in Explanted Lungs

BACKGROUND

Recurrence and overall survival for incidental lung cancer in explanted lungs vary between different series. Recurrence patterns are also not well described. The primary objective of this study is to study the recurrence patterns and time to recurrence for various stages of lung cancer in lung transplant recipients.

METHODS

A retrospective review of our institutional database was performed to identify patients who had incidental lung cancer found in transplant pneumonectomy specimens from 1990 to 2017. Demographic, radiographic, and perioperative clinical variables were collected. Time to recurrence, overall survival, and recurrence patterns were recorded. Freedom from recurrence and overall survival were estimated by using Kaplan-Meier analysis.

RESULTS

Thirty-one patients had unexpected malignancy and 29 patients (1.6%) had primary lung carcinoma in the explanted lung. Indication for transplantation was chronic obstructive pulmonary disease in 15 patients (48%) and interstitial lung disease for 16 patients (52%). Preoperative imaging showed indeterminate nodules in 10 patients (32%). Pathologic review showed stage I disease in 15 patients (54%), stage II disease in 10 patients (35%), and stage III disease in 2 patients (7%). Recurrence was noted in 8 patients (28%). Most patients had nodal disease (25%) or systemic recurrence (75%). All recurrences occurred within 2 years of the transplantation. For patients with stage I and II disease, freedom from recurrence at 1, 3, and 5 years was 91%, 55%, and 55%, respectively. Overall survival at 1, 3, and 5 years was 78%, 18%, and 14%, respectively.

CONCLUSIONS

Most recurrences occur within 2 years after transplantation and are the cause of death in these patients. Patients with nodal disease tend to have higher recurrence rates. Multidisciplinary review of abnormal radiographic findings before transplantation and close follow-up may allow for detection of undiagnosed cancers.