Multifocal Lung Cancer Discussion and Case Presentation

Introduction

Multifocal lung cancer is an increasingly common clinical scenario, but there is a lack of high-level evidence for its optimal treatment [1]. Staging is an important first step in the management of such pathologies. As many as six percent of patients may present with unsuspected cranial metastases [2]. Minimally invasive resections, parenchymal-sparing approaches, and multidisciplinary care are the central themes emphasized in this case report and review of the literature.

Case

A 69-year-old woman who was an active tennis player presented with a prior history of right upper lobe lung cancer that was discovered incidentally on low dose screening chest CT scan. She is a former smoker with a 25-30 pack year history, but quit 25 years ago. Once removed, her previous tumor was pathologically staged as a well-differentiated adenocarcinoma, stage IIB, N0, M0. She underwent a right posterolateral open thoracotomy with right upper lobectomy in 2013, with postoperative adjuvant chemotherapy. Four years later, she presented with multiple foci of new suspicious lesions on surveillance scans, predominantly located in the left lower lobe of the lung. There were no new lesions that were suspicious on the right lung. The results of her pulmonary lung function tests showed adequate pulmonary reserve for another lobectomy. The authors discussed her care in their Multidisciplinary Lung Ablation Tumor Board. The left lower lobe predominant lesion gave an intermediate probability of invasive adenocarcinoma based on her Canary analysis (the predicted probability of the nodule being adenocarcinoma). Her positron emission tomography scan was negative for extrathoracic or mediastinal disease. Brain magnetic resonance imaging was negative for malignant lesions. She underwent endobronchial ultrasound fine needle aspiration, and all mediastinal lymph nodes were negative for malignant disease. 

Results

The left lower lobe resection was uncomplicated (Video 1). Lymph node stations 5, 7, 9L, 10L, 11L, and multiple intrapulmonary peribronchial lymph nodes were negative for tumor, with a total of 22 nodes sampled during the surgery. Within the left lower lobe of the lung, the pathologic assessment revealed adenocarcinoma forming 10 nodules that ranged in size from 0.4 - 1.0 cm, with each tumor having a negative margin. The patient was discharged on postoperative day three.

Conclusion

The management of patients with multifocal lung cancer can be difficult due to several factors. Discriminating between metastatic disease and separate primary lesions is important, and published criteria may guide oncologic care planning [3-5]. When technically resecting a left lower lobe of the lung, it is possible to take the lung sequentially from a bottom-up approach, if safe: dividing the vein, followed by the bronchus, and finally the artery. One should make sure the superior segmental branch of the pulmonary artery has been taken, as well as the bronchus, when dividing these branches.

In the setting of multifocal lesions, the approach should be to resect the least amount of lung in the least invasive manner the first time, but with the best cancer resection to preserve lung. This will provide the patient with better options in the setting of the other ground glass opacities or nodules progressing. In patients with adequate pulmonary reserve, another parenchymal-sparing approach should then be considered, if they present with new cancers. Extraordinary measures should be taken only after multidisciplinary thoracic tumor board discussions in experienced centers [6-9].

References

1. Leventakos K, Peikert T, Midthun DE, et al. Management of multifocal lung cancer: results of a survey. J Thorac Oncol. 2017;12(9):1398-1402. 
2. Leventakos K, Mansfield AS, Blackmon S, et al. 88P: Use of brain imaging in the management of patients with lymph node negative multifocal lung cancer. J Thorac Oncol. 2016;11(4 suppl):S93-S94.
3. Martini N, Melamed MR. Multiple primary lung cancers. J Thorac Cardiovasc Surg. 1975;70(4):606-612.
4. Antakli T, Schaefer RF, Rutherford JE, Read RC. Second primary lung cancer. AnnThorac Surg. 1995;59(4):863-867.
5. Shen KR, Meyers BF, Larner JM, Jones DR, American College of Chest Physicians. Special treatment issues in lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition). Chest. 2007;132(3 suppl):290S-305S.
6. Deschamps C, Pairolero PC, Trastek VF, Payne WS. Multiple primary lung cancers. Results of surgical treatment. J Thorac Cardiovasc Surg. 1990;99(5):769-777.
7. Yang J, Liu M, Fan J, et al. Surgical treatment of metachronous second primary lung cancer. Ann Thorac Surg. 2014;98(4):1192-1198.
8. Taioli E, Lee DS, Kaufman A, et al. Second Primary Lung Cancers Demonstrate Better Survival with Surgery than Radiation. Semin Thorac Surg. 2016;28(1):195-200. 
9. Rice D, Kim HW, Sabichi A, et al. The risk of second primary tumors after resection of stage I nonsmall cell lung cancer. Ann Thorac Surg. 2003;76(4):1001-1008.