Synchronous multiple primary lung cancer: An increasing clinical occurrence requiring multidisciplinary management

Dosimetric comparison of IMPT vs VMAT for multiple lung lesions: an NTCP model-based decision-making strategy

To compare the dosimetric differences in volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) in stereotactic body radiation therapy (SBRT) of multiple lung lesions and determine a normal tissue complication probability (NTCP) model-based decision strategy that determines which treatment modality the patient will use. A total of 41 patients were retrospectively selected for this study. The number of patients with 1-6 lesions was 5, 16, 7, 6, 3, and 4, respectively. A prescription dose of 70 GyRBE in 10 fractions was given to each lesion. SBRT plans were generated using VMAT and IMPT. All the IMPT plans used robustness optimization with ± 3.5% range uncertainties and 5 mm setup uncertainties. Dosimetric metrics and the predicted NTCP value of radiation pneumonitis (RP), esophagitis, and pericarditis were analyzed to evaluate the potential clinical benefits between different planning groups. In addition, a threshold for the ratio of PTV to lungs (%) to determine whether a patient would benefit highly from IMPT was determined using receiver operating characteristic curves. All plans reached target coverage (V70GyRBE ≥ 95%). Compared with VMAT, IMPT resulted in a significantly lower dose of most thoracic normal tissues. For the 1-2, 3-4 and 5-6 lesion groups, the lung V5 was 29.90 ± 9.44%, 58.33 ± 13.35%, and 81.02 ± 5.91% for VMAT and 11.34 ± 3.11% (p < 0.001), 21.45 ± 3.80% (p < 0.001), and 32.48 ± 4.90% (p < 0.001) for IMPT, respectively. The lung V20 was 12.07 ± 4.94%, 25.57 ± 6.54%, and 43.99 ± 11.83% for VMAT and 6.76 ± 1.80% (p < 0.001), 13.14 ± 2.27% (p < 0.01), and 19.62 ± 3.48% (p < 0.01) for IMPT. The Dmean of the total lung was 7.65 ± 2.47 GyRBE, 14.78 ± 2.75 GyRBE, and 21.64 ± 4.07 GyRBE for VMAT and 3.69 ± 1.04 GyRBE (p < 0.001), 7.13 ± 1.41 GyRBE (p < 0.001), and 10.69 ± 1.81 GyRBE (p < 0.001) for IMPT. Additionally, in the VMAT group, the maximum NTCP value of radiation pneumonitis was 73.91%, whereas it was significantly lower in the IMPT group at 10.73%. The accuracy of our NTCP model-based decision model, which combines the number of lesions and PTV/Lungs (%), was 97.6%. The study demonstrated that the IMPT SBRT for multiple lung lesions had satisfactory dosimetry results, even when the number of lesions reached 6. The NTCP model-based decision strategy presented in our study could serve as an effective tool in clinical practice, aiding in the selection of the optimal treatment modality between VMAT and IMPT.

Predictors of residual simultaneous multiple ground-glass nodule progression after dominant lesion resection

OBJECTIVE

This study aimed to identify the predictive factors for the progression of residual simultaneous multifocal ground-glass nodules (SMGGNs) after resection of the dominant lesion.

METHODS

Patients (n = 3420) with primary lung cancer who underwent lung resections at our hospital between 2006 and 2016 were screened, and the data from 82 patients who had residual SMGGNs after undergoing surgery for the dominant lesion (pathologically stage 0-IIA) were retrospectively analyzed. Clinicopathological factors that predicted the growth of residual second dominant GGNs were identified.

RESULTS

Median total tumor and solid component sizes of the residual second dominant GGNs were 1.3 cm (interquartile range [IQR]: 0.6-2.0) and 0 cm (IQR: 0-0.7), respectively. During a median follow-up period of 54 months (IQR: 37-78 months), 35 (43%) lesions progressed. Logistic regression analysis revealed that age younger than 70 (OR: 10.54, 95% CI: 1.71-65.11), a dominant lesion with pure solid appearance (reference: GGN, OR: 18.16, 95% CI: 1.66-198.60), a second dominant GGN total size larger than 1.0 cm (OR: 12.27, 95% CI: 1.85-81.17), and a second dominant GGN solid component size larger than 0.5 cm (OR: 17.59, 95% CI: 3.58-86.47) were significant predictive factors for the progression of residual GGNs (all p values < 0.03). Based on an analysis of growth patterns, rapid growth was higher in second dominant GGNs with a part-solid appearance.

CONCLUSIONS

If the resected dominant lesion or the residual second dominant GGN exhibits high-risk factors, the second dominant GGN should be meticulously observed.

Genomic characteristics and immune landscape of super multiple primary lung cancer

BACKGROUND

In recent years, a growing number of patients with multiple primary lung cancer (MPLC) are being diagnosed, and a subset of these patients is found to have a large number of lesions at the time of diagnosis, which are referred to as 'super MPLC'.

METHODS

Here, we perform whole exome sequencing (WES) and immunohistochemistry (IHC) analysis of PD-L1 and CD8 on 212 tumor samples from 42 patients with super MPLC.

FINDINGS

We report the genomic alteration landscape of super MPLC. EGFR, RBM10 and TP53 mutation and TERT amplification are important molecular events in the evolution of super MPLC. We propose the conception of early intrapulmonary metastasis, which exhibits different clinical features from conventional metastasis. The IHC analyses of PD-L1 and CD8 reveal a less inflamed microenvironment of super MPLC than that of traditional non-small cell lung cancer (NSCLC). We identify the potentially susceptible germline mutations for super MPLC.

INTERPRETATION

Our study depicts the genomic characteristics and immune landscape, providing insights into the pathogenesis and possible therapeutic guidance of super MPLC.

FUNDING

A full list of funding bodies that supported this study can be found in the Acknowledgements section.

Lobar or sublobar resection for early-stage second primary lung cancer ≤ 3 cm in size: a SEER population-based study

PURPOSE

Surgical strategy for second primary lung cancer (SPLC) may be more conservative due to influence of first primary lung cancer (FPLC). The optimal surgical method for SPLC warrants discussion. We aimed to explore a more suitable surgical approach for early-stage (T1-T2N0, ≤ 3 cm) SPLC and provide insights for clinical practice.

METHODS

A retrospective study was conducted using data from the Surveillance, Epidemiology and End Results database between 2004 and 2018, and data of patients with early-stage SPLC who underwent secondary surgery were collected. Propensity score matching (PSM) reduced potential bias between lobar and sublobar resection groups. The effect of lobar and sublobar resection on overall survival (OS) was assessed in all patients and subgroups.

RESULTS

A total of 714 patients who met the study entry criteria were enrolled, including 476 patients in the sublobar resection group (66.67%) and 238 patients in the lobar resection group (33.33%). There was no difference in OS between the lobar and sublobar resection groups before and after PSM (P = 0.289) and (P = 0.608), respectively. Subgroup analyses showed that lobar resection achieved a significantly better OS than sublobar resection only in patients with an SPLC tumor size of 2-3 cm (P < 0.05).

CONCLUSION

The OS of sublobar resection was not significantly different from that of lobar resection for early-stage SPLC. For SPLC with a 2-3 cm tumor size, lobar resection is more advantageous than sublobar resection.

A pairwise radiomics algorithm-lesion pair relation estimation model for distinguishing multiple primary lung cancer from intrapulmonary metastasis

Background

Distinguishing multiple primary lung cancer (MPLC) from intrapulmonary metastasis (IPM) is critical for their disparate treatment strategy and prognosis. This study aimed to establish a non-invasive model to make the differentiation pre-operatively.

Methods

We retrospectively studied 168 patients with multiple lung cancers (307 pairs of lesions) including 118 cases for modeling and internal validation, and 50 cases for independent external validation. Radiomic features on computed tomography (CT) were extracted to calculate the absolute deviation of paired lesions. Features were then selected by correlation coefficients and random forest classifier 5-fold cross-validation, based on which the lesion pair relation estimation (PRE) model was developed. A major voting strategy was used to decide diagnosis for cases with multiple pairs of lesions. Cases from another institute were included as the external validation set for the PRE model to compete with two experienced clinicians.

Results

Seven radiomic features were selected for the PRE model construction. With major voting strategy, the mean area under receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity of the training versus internal validation versus external validation cohort to distinguish MPLC were 0.983 versus 0.844 versus 0.793, 0.942 versus 0.846 versus 0.760, 0.905 versus 0.728 versus 0.727, and 0.962 versus 0.910 versus 0.769, respectively. AUCs of the two clinicians were 0.619 and 0.580.

Conclusions

The CT radiomic feature-based lesion PRE model is potentially an accurate diagnostic tool for the differentiation of MPLC and IPM, which could help with clinical decision making.

Synchronous multiple lung cancers with hilar lymph node metastasis of small cell carcinoma: A case report

BACKGROUND

Synchronous multiple lung cancers are rare and refer to the simultaneous presence of two or more primary lung tumors, which present significant challenges in terms of diagnosis and treatment.

CASE SUMMARY

We report a case of multiple synchronous lung cancers with hilar lymph node metastasis of small cell carcinoma of unknown origin in a 73-year-old man. Transbronchial lung biopsy revealed squamous cell carcinoma. Although enlargement of lymph node 12u was detected, no distant metastases were observed. The patient was preoperatively diagnosed with T1cN0M0 and underwent thoracoscopic right upper lobectomy with nodal dissection (ND2a). Based on histopathological findings, the primary lesion was squamous cell carcinoma. A microinvasive adenocarcinoma was also observed on the cranial side of the primary lesion. Tumors were detected in two resected lymph nodes (#12u and #11s). Both tumors were pathologically diagnosed as small cell carcinomas. The primary lesion of the small cell carcinoma could not be identified even by whole-body imaging; however, chemotherapy was initiated for hilar lymph node metastasis of the small cell carcinoma of unknown origin.

CONCLUSION

Multiple synchronous lung cancers can be accompanied by hilar lymph node metastasis of small cell carcinomas of unknown origin.

Sublobar resection versus lobectomy in the treatment of synchronous multiple primary lung cancer

OBJECTIVE

Although synchronous multiple primary lung cancers (sMPLCs) are common in clinical practice, the choice of surgical modalities for the main lesion is still at the stage of exploration. This study is designed to analyze the prognosis of sMPLCs and single primary lung cancers with similar tumor stages and to explore whether sublobar resection has a similar prognosis as lobectomy for sMPLCs.

METHODS

One-hundred forty-one cases of sMPLCs were selected, including the following: 65 cases underwent lobectomy for main lesions, and 76 cases underwent sublobar resection for main lesions. One thousand one hundred forty-four cases of single primary lung cancer were matched at 1:1 by propensity score matching. Then, the patients with sMPLCs were divided into a lobectomy group and a sublobar group according to the first tumor stage. Ninety-eight cases of patients with sMPLCs were matched. The short-term perioperative effect, 5-year disease-free survival (DFS) rate, and 5-year overall survival (OS) rate between the two groups were compared.

RESULTS

There was no significant difference in OS between sMPLCs and single primary lung cancer after lobectomy (77.1% vs. 77.2%, P = 0.157) and sublobar resection (98.7% vs. 90.7%, P = 0.309). There was no significant difference in OS (86.7% vs. 83.9%, P = 0.482) or DFS (67.6 vs. 87.7%, P = 0.324) between the lobectomy group and sublobar group with sMPLCs. The sublobar resection group obtained a lower incidence of postoperative complications (40.8% vs. 16.3%, P = 0.007) and shorter postoperative hospital stay (11.22 vs. 9.27, P = 0.049).

CONCLUSION

The prognosis of patients with sMPLCs generally depends on the main tumor state, which has no statistical difference regardless of sublobar resection or lobectomy, and the perioperative period of sublobar resection is safer than that of lobectomy.

Association of the Extent of Resection with Survival in Multiple Primary Lung Cancer: A Systematic Review

BACKGROUND

The incidence of synchronous multiple primary lung cancer (SMPLC) has progressively increased, due to recent advances in imaging. To date, no guidelines defining recommendations for patients' selection and no standard treatment of cases with SMPLC have been defined.The primary aim of this systematic review was to assess survival among patients treated with lobectomy or sublobar resection MPLC.

METHODS

Comprehensive literature search of Medline, the Cochrane Library, reference lists, and ongoing studies was performed according to a prospectively registered design (PROSPERO: CRD42019115487). All studies published between 1998 and December 2020 that examined treatments with lobectomy compared to sublobar resection were included. Two double-blind investigators independently selected articles.Primary outcomes were to assess the 5-year overall survival (OS) rate among patients treated with lobectomy or sublobar resection and the impact of lymph node status on 5-year OS and 5-year disease-free survival in patients with MPLC.

RESULTS

The search yielded 424 articles; 4 observational studies met the inclusion criteria and collectively evaluated 298 patients with a mean age ranging from 61.5 to 67 years. A total of 112 patients were treated for bilateral synchronous tumors and 186 patients for unilateral multiple synchronous tumors. All included studies showed that the type of resection, lobectomy or limited resection, had no significant impact on survival.

CONCLUSION

Limited resection is a valuable treatment option for MPLC. However, the clinical level of evidence of the studies found is low and randomized studies are needed to clarify the extent of resection in MPLC.

Prognostic Factors for Survival in Multiple Primary Lung Adenocarcinomas: A Retrospective Analysis of 283 Patients

Purpose: In recent years, a rising number of multiple primary lung cancers have been detected with the advancement of imaging technology. No detailed study has assessed the prognosis of multiple primary lung adenocarcinomas based on computed tomography characteristics. The present study aimed to analyze outcomes and determine valuable factors for predicting the prognosis of multiple primary lung adenocarcinoma. Methods: This single-center retrospective study was performed from January 2013 to October 2021. All patients were divided into 3 groups based on tumor density as follows: multi-pure ground-glass nodules, at least one part-solid nodule without solid nodules, and at least one solid nodule. Clinicopathologic features, computed tomography signs, and survival outcomes were compared between these groups. The Kaplan-Meier method was used for survival analysis. The multivariable Cox proportional hazards regression model was used to identify independent predictors for recurrence-free survival and overall survival. Results: The sample included 283 patients with 623 lesions who met the inclusion criteria for multiple primary lung adenocarcinoma. Of these patients, 71 (25.1%) presented with multi-pure ground-glass nodules, 100 (35.3%) with at least one part-solid nodule without solid nodule, and 112 (39.6%) with at least one solid nodule. The 3 groups had distinguished clinicopathologic and radiological features of age, adjuvant therapy, types of tumor resection, TNM stage, pathological subtypes, pleural indentation, spicule, and vacuole (all P < .001). Multivariate analysis found that lesion number was an independent predictor for both recurrence-free survival (hazard ratio 2.41; 95% confidence interval 1.12-5.19; P = .025) and overall survival (hazard ratio 4.78; 95% confidence interval 1.88-12.18; P = .001), and the at least one solid nodule was an independent predictor for overall survival (hazard ratio 5.307; 95% confidence interval 1.16-24.31; P = .032). Stage III (hazard ratio 5.71; 95% confidence interval 1.94-16.81; P = .002) and adjuvant therapy (hazard ratio 2.52; 95% confidence interval 1.24-5.13; P = .011) influenced the recurrence-free survival. Conclusions: Survival of multiple primary lung adenocarcinoma patients is strongly correlated with the lesion number and the at least one solid nodule tumors in radiological. This information may be useful for predicting survival and making clinical decisions in future studies.

Application of Dynamic 18F-FDG PET/CT for Distinguishing Intrapulmonary Metastases from Synchronous Multiple Primary Lung Cancer

It has been a big challenge to distinguish synchronous multiple primary lung cancer (sMPLC) from primary lung cancer with intrapulmonary metastases (IPM). We aimed to assess the clinical application of dynamic ¹⁸F-FDG PET/CT in patients with multiple lung cancer nodules. We enrolled patients with multiple pulmonary nodules who had undergone dynamic ¹⁸F-FDG PET/CT and divided them into sMPLC and IPM groups based on comprehensive features. The SUV_max, fitted K_i value based on dynamic scanning, and corresponding maximum diameter (D_max) from the two largest tumors were determined in each patient. We determined the absolute between-tumor difference of SUV_max/D_max and K_i/D_max (ΔSUV_max/D_max; ΔK_i/D_max) and assessed the between-group differences. Further, the diagnostic accuracy was evaluated by ROC analysis and the correlation between ΔSUV_max/D_max and ΔK_i/D_max from all groups was determined. There was no significant difference for ΔSUV_max/D_max between the IPM and sMPLC groups, while the IPM group had a significantly higher ΔK_i/D_max than the sMPLC group. The AUC of ΔK_i/D_max for differentiating sMPLC from IPM was 0.80 (cut-off value of K_i = 0.0059, sensitivity 79%, specificity 75%, p < 0.001). There was a good correlation (Pearson r = 0.91, 95% CI: 0.79-0.96, p < 0.0001) between ΔSUV_max/D_max and ΔK_i/D_max in the IPM group but not in the sMPLC group (Pearson r = 0.45, p > 0.05). Dynamic ¹⁸F-FDG PET/CT could be a useful tool for distinguishing sMPLC from IPM. K_i calculation based on Patlak graphic analysis could be more sensitive than SUV_max in discriminating IPM from sMPLC in patients with multiple lung cancer nodules.

MTA1 Expression Can Stratify the Risk of Patients with Multifocal Non-Small Cell Lung Cancers ≤3 cm

Purpose

Currently, there is no uniform standard to guide postoperative adjuvant chemotherapy for patients with multifocal non-small cell lung cancers (NSCLCs) ≤3 cm. Therefore, there is an urgent need to explore prognostic molecular markers to identify high-risk patients with multifocal NSCLCs ≤3 cm. We aimed to explore the potential value of metastasis-associated protein 1(MTA1) expression in risk stratification of patients with multifocal NSCLCs ≤3 cm.

Methods

We retrospectively analyzed the clinical data and postoperative survival data of patients with multifocal NSCLCs ≤3 cm. Paraffin-embedded tissue sections were used for immunohistochemistry. Semiquantitative immunoreactivity scoring (IRS) system was used to evaluate the nuclear expression of MTA1. SPSS software (version 23.0) was used to analyze the data.

Results

The IRS of MTA1 nuclear expression in 259 lesions of 119 patients ranged from 2.2 to 11.7 (median: 5.6). Our results showed that MTA1 expression was highest in high-risk pathological subtypes of lung adenocarcinoma. MTA1 expression in multiple primary lung cancers (MPLCs) was lower than that in intrapulmonary metastases (IPMs). The median follow-up duration was 25.97 months. The disease-free survival (DFS) of patients with MPLCs was significantly better than that of patients with IPMs, and the DFS of patients with high MTA1 expression was significantly worse than that of patients with low MTA1 expression. Multivariate Cox analysis showed that high MTA1 expression (hazard ratio: 7.937, 95% confidence interval: 2.433–25.64, p =0.001) was a statistically significant predictor of worse DFS in patients with multifocal NSCLCs ≤3 cm.

Conclusion

MTA1 expression can stratify the risk in patients with multifocal NSCLCs ≤3 cm. Patients with MTA1 immunohistochemical score >5.6 are at a high risk of postoperative recurrence, and these patients may benefit from postoperative adjuvant chemotherapy.

The Role of Whole Exome Sequencing in Distinguishing Primary and Secondary Lung Cancers

Non-small cell lung cancer (NSCLC) that presents with multiple lung tumors (MLTs) poses a challenge to accurate staging and prognosis. MLTs that arise as clonally related secondary metastases from a common primary are higher stage and often require adjuvant chemotherapy or may in fact be incurable stage IV lesions. Conversely, MLTs that represent distinct primaries have a better prognosis and may be overtreated if inappropriately classified as related secondaries. Historically, pathologic and radiographic criteria were used to distinguish between primary and secondary MLTs; however, the advent of genomic profiling has demonstrated limitations to these historic classification systems. In this review, we discuss the use of molecular profiling to distinguish between primary and secondary lung cancers, with a focus on the insights gleaned from whole exome sequencing (WES) analyses. While WES is not yet feasible in routine clinical practice, WES studies have helped elucidate the clonal relationship between primary and secondary lung cancers and provide important context for the application of targeted sequencing panel-based analyses.

Surgical treatment for synchronous multiple primary lung cancer: Is it possible to achieve both curability and preservation of the pulmonary function?

BACKGROUND

With the advent of high-resolution chest imaging, the number of patients diagnosed with multiple primary lung cancers is increasing. For the treatment of multiple lung cancers, a surgical procedure that preserves pulmonary function while ensuring curability is required.

METHODS

The study population included 85 patients with synchronous multiple primary lung cancer who received surgical resection between January 2010 and September 2020. Patients with synchronous lung cancer within the same lobe were excluded, and only patients with ≥2 involved lobes were included. The postoperative pulmonary function was examined at 3-6 months after the surgery.

RESULTS

Sixty-seven patients had cancers within the ipsilateral lobe, and 18 patients had cancers in bilateral lobes. Seventy-six patients (89.4%) underwent combination surgery with limited resection (e.g., segmentectomy and wedge resection). The preoperative pulmonary functions (mean VC/%VC, mean FEV₁ /%FEV₁ , and mean %DLCO) were 3.06 L/100.2%, 2.23 L/96.1%, and 117.2%, respectively, and the postoperative pulmonary functions were 2.45 L/81.4%, 1.87 L/81.2%, and 102.6%. In each parameter, the predicted reductions of pulmonary function were almost the same as the predicted values. The 5-year survival rate was 85.0%. The 5-year survival rate according to the most advanced pathological stage was 94.9% for stage I disease, and 62.6% for stage ≥II, which was a significant difference (p < 0.001).

CONCLUSIONS

Surgical treatment including limited resection, especially segmentectomy and wedge resection, for synchronous multiple primary lung cancer can preserve pulmonary function while ensuring curability.

Guiding Principles in the Management of Synchronous and Metachronous Primary Non-Small Cell Lung Cancer

Multiple lung cancers can be found simultaneously, with incidence ranging from 1% to 8%. Documentation of more than 1 pulmonary lesion can be challenging, because these solid, ground-glass, or mixed-density tumors may represent multicentric malignant disease or intrapulmonary metastases. If mediastinal nodal and distant deposits are excluded, surgery should be contemplated. After surgical treatment of lung cancer, patients should be followed closely for an undetermined period of time. Good clinical judgment is of outmost importance in deciding which individuals will benefit from those surgical interventions and which are candidates for alternate therapies. Every case should be discussed in a multidisciplinary meeting.

Middle lobe preservation and fixation after right upper and lower lobectomy for synchronous lung cancer

The incidence of multiple lung cancer has been steadily increasing worldwide. Although cases of patients with lung cancers in the right upper and lower lobe have also become more frequently reported in clinical work, simultaneous right upper and lower lobectomy reports with the middle lobe preservation are still quite rare. A total of three patients with lung cancers in the right upper and lower lobe were included in the study. The patients underwent simultaneous right upper and lower lobectomy, whereas the remaining middle lobe was sutured and fixed to the intercostal muscle of the incision to prevent postoperative lobe torsion. There was no procedure to reduce residual space，such as phrenic nerve crush or thoracoplasty. All patients were discharged from the hospital 7 days after the operation. The chest tube was removed 5 days after the operation in two patients. One patient was discharged with the tube because of slight pulmonary leakage, and the tube was removed 2 weeks after the operation. Six months after the operation, the chest computer tomography showed that the middle lobe expanded well and no obvious cavity or pleural effusion was found. The suture of the remaining middle lobe and intercostal muscle of the incision is a simple and effective method that can be used to successfully avoid middle lobe torsion. This strategy is safe and can be used as the first choice for eligible patients.

A multidisciplinary approach for the differential diagnosis between multiple primary lung adenocarcinomas and intrapulmonary metastases

PURPOSE

The distinction between multiple primary lung cancers (MPLCs) and intrapulmonary metastases has a significant impact on tumor staging and therapeutic choices. Several criteria have been proposed to solve this diagnostic issue, but a definitive consensus is still missing. We tested the efficacy of a combined clinical, histopathological and molecular ("real world") approach for the correct classification of multiple lung tumors in a selected cohort of patients.

METHODS

24 multiple lung tumors with a diagnosis of adenocarcinoma from 10 patients were retrospectively reviewed. Radiological, pathological and clinical information, including follow-up, were integrated with molecular profiling via a routine multigene panel sequencing.

RESULTS

Comprehensive histologic assessment revealed readily distinguishable histologic patterns between multiple tumors suggesting unrelated lesions in 7 cases, in agreement with clinical, radiological and molecular data, thus leading to final diagnosis of MPLCs. In the remaining 3 cases, the differential diagnosis between MPLCs and intrapulmonary metastases was challenging, since the histologic features of the lesions were similar or identical. The final interpretation (2 MPLCs and 1 most likely intrapulmonary metastases) was reached thanks to the integration of all available data, and was confirmed by follow-up.

CONCLUSIONS

A multidisciplinary approach including a routinely affordable multigene panel sequencing is a useful tool to discriminate MPLCs from intrapulmonary metastases in multiple lung nodules sharing the adenocarcinoma histotype.

Small cell carcinoma of the lung in a patient with previously treated synchronous adenocarcinoma and squamous cell carcinoma

A 66-year-old Caucasian female with a 40-pack-year history of smoking and chronic obstructive pulmonary disease presented for follow-up of synchronous multiple primary lung cancers: Stage IB left upper lobe adenocarcinoma and Stage IA right middle lobe (RML) squamous cell carcinoma. The patient was treated with left upper lobectomy and RML pulmonary wedge resection 5 years prior. Surveillance chest computed tomography showed an increase in the size of the subcarinal lymph node and right lymph node conglomerate encasing the right upper lobe pulmonary artery, consistent with metastasis. Fine-needle aspiration of level 4R lymph nodes was performed. Histology and immunohistochemical staining confirmed the diagnosis of small cell carcinoma. Consequently, the patient was placed on cisplatin/etoposide combination chemotherapy.

Characteristics and prognosis of synchronous multiple primary lung cancer after surgical treatment: A systematic review and meta-analysis of current evidence

Background

This study aims to quantitatively summary the characteristics of synchronous multiple primary lung cancer (sMPLC), postoperative mortality, long‐term prognosis, and prognostic effects of potential clinical parameters in patients with sMPLC after surgery.

Methods

PubMed and Embase databases were systematically searched to identify studies that explored the prognosis of patients with sMPLC after surgery.

Results

Fifty‐two studies with 3486 participants were included, and clinical characteristics were quantitatively summarized. The pooled proportion of sMPLC in lung cancer was 2.0% (95%CI, 1.6%–2.5%) with an increasing trend over time, and postoperative mortality was 1.4% (95%CI, 0.5%–2.7%) with a decreasing trend over time. The 5‐year survival rate was 44.9% (95%CI, 37.4%–52.6%) and all long‐term survival rates showed increasing trends over time. Poor long‐term prognosis was observed in both limited resection (HR = 1.357, 95%CI, 1.047–1.759, p = 0.0210) and pneumonectomy (HR = 2.643, 95%CI, 1.539–4.541, p = 0.0004) by comparison of anatomical resection. Other clinical parameters of age, gender, smoking status, FEV1, and lymph node metastasis significantly impacted the long‐term prognosis (all p < 0.05).

Conclusions

The proportion of sMPLC in lung cancer and 5‐year survival rate are increasing, while postoperative mortality is decreasing trend over time. Lobectomy should be preferred, while pneumonectomy should be avoided for sMPLC. Age, gender, FEV1, smoking, tumor size, surgical methods, and lymph node status are prognostic factors for sMPLC. Considering the heterogeneity and publication bias, these findings should be treated with caution.

Surgical Prognosis of Synchronous Multiple Primary Lung Cancer: Systematic Review and Meta-Analysis

BACKGROUND

We evaluated the long-term prognosis of synchronous multiple primary lung cancer (SMPLC) patients after surgical treatment and explored prognostic factors for overall survival (OS).

MATERIALS AND METHODS

A systematic review and meta-analysis was performed regarding the surgical prognosis of SMPLC. A literature search was performed using online databases. All studies were rigorously categorized following the 8th edition of the tumor, node, metastasis classification (TNM) staging rules for multiple lung cancers: SMPLC and multifocal ground-glass/lepidic (GG/L) lung cancers. Five-year OS after surgery was pooled, and hazard ratios (HRs) for prognostic factors were synthesized. Specific subgroup analysis and sensitivity analysis were conducted (PROSPERO registration CRD42019142420).

RESULTS

An analysis of 26 studies including 1788 patients was performed. The pooled 5-year OS was 45% (95% confidence interval [CI], 37-53) of true SMPLC patients and 62% (95% CI, 57-67) of patients with pathologic stage I disease, which was different from the 5-year OS of 93% (95% CI, 85-100) of patients with multifocal GG/L lung cancers. Poor prognostic factors for SMPLC were lymph node metastasis (HR = 2.36; 95% CI, 1.75-3.20; P < .001) and pneumonectomy (HR = 2.96; 95% CI, 1.36-6.45; P = .006], whereas histology (HR = 1.11; 95% CI, 0.82-1.50; P = .508), laterality (HR = 1.16; 95% CI, 0.93-1.44, P = .190), sublobar resection (HR = 1.29; 95% CI, 0.90-1.84; P = .159), and adjuvant therapy (HR = 1.07; 95% CI, 0.64-1.80; P = .791) were not found to influence the outcome.

CONCLUSION

The long-term prognosis of SMPLC patients after surgery is acceptable, especially in patients with early-stage disease. Sublobar resection can be applied, although pneumonectomy should be avoided. Advanced criteria are needed to diagnose SMPLC and distinguish it from multifocal GG/L lung cancer to perform accurate surgical evaluation.

A rare case of synchronous multiple primary lung cancer with different responses to gefitinib

Differentiating multiple primary lung cancer (MPLC) from lung metastasis is important, and the pathology and gene mutations may be different between the tumors. A lung biopsy to differentiate lesions should be considered, especially when the response of different tumors to treatment is distinct.

Multiple Primary Lung Cancers: A New Challenge in the Era of Precision Medicine

With the widespread implementation of lung cancer screening, more and more patients are being diagnosed with multiple primary lung cancers (MPLCs). In the era of precision medicine, many controversies remain in differentiating MPLCs from intrapulmonary metastasis and the optimum treatment choice, especially in patients exhibiting similar histology. In this review, we summarize common diagnostic criteria and novel discrimination methods with a special emphasis on the emerging value of broad panel next-generation sequencing (NGS) for the diagnosis of MPLCs. We then discuss current advances regarding therapeutic approaches for MPLCs. Radical surgery is the main treatment modality, while stereotactic body radiotherapy (SBRT) is safe and feasible for early-stage MPLC patients with inoperable tumors. In addition, immunotherapy and targeted therapy, particularly epidermal growth factor receptor-tyrosine kinase inhibitors, are emerging therapeutic strategies that are still in their infancy. Characteristics of both genomic profiles and tumor microenvironment are currently being evaluated but warrant further exploration to facilitate the application of targeted systematic therapies in MPLC patients.

Distinguishing multiple lung primaries from intra-pulmonary metastases and treatment implications

INTRODUCTION

The distinction between multiple primary lung cancers and intra-pulmonary metastases has been extensively investigated because of its important clinical and therapeutic implications.

AREAS COVERED

Rapidly improving imaging technology and genomic analysis has led to a finer discrimination between multiple primary lung tumors and pulmonary metastases. However, over the past few decades, standardized criteria for the identification of multiple lung tumors have been lacking. Therefore, in 2017 a multidisciplinary international committee composed of the Union for International Cancer Control (UICC), American Joint Committee on Cancer (AJCC) and International Association for the Study of Lung Cancer (IASLC) addressed this problem when drawing up the 8th edition of TMN stage classification, that now represents a specific consensus on this topic. The most advanced diagnostic strategies associated with screening allow for the detection of early stage synchronous lung cancers.

EXPERT OPINION

Although diagnostic confirmation relies on pathologic and clinical examination, new molecular analyses help in the discrimination between primary and secondary tumors. The treatment of multiple primary lung tumors remains, whenever possible, a local treatment based on surgical resection, providing the absence of distant or local (lymph node) metastases.

Outcomes after Contralateral Anatomic Surgical Resection in Multiple Lung Cancer

BACKGROUND

Patients treated surgically for lung cancer may present synchronous or metachronous lung cancers. The aim of this study was to evaluate outcomes after a second contralateral anatomic surgical resection for lung cancer.

METHODS

We performed a retrospective two-center study, based on a prospective indexed database. Included patients were treated surgically by bilateral anatomic surgical resection for a second primary lung cancer. We excluded nonanatomic resections, benign lesions, and ipsilateral second surgical resections.

RESULTS

Between January 2011 and September 2018, 55 patients underwent contralateral anatomic surgical resections for lung cancer, mostly for metachronous cancers. The first surgical resection was a lobectomy in most cases (45 lobectomies: 81.8%, 9 segmentectomies: 16.4%, and 1 bilobectomy: 1.8%), and a video-assisted thoracic surgery (VATS) procedure was used in 23 cases (41.8%). The mean interval between the operations was 38 months, and lobectomy was less frequent for the second surgical resection (35 lobectomies: 63.6% and 20 segmentectomies: 36.4%), with VATS procedures performed in 41 cases (74.5%). Ninety-day mortality was 10.9% (n = 6), and 3-year survival was 77%. Risk factor analysis identified the number of resected segments during the second intervention or the total number of resected segments, extent of resection (lobectomy vs. segmentectomy), surgical approach (thoracotomy vs. VATS), tumor stage, and nodal involvement as potential prognostic factors for long-term survival.

CONCLUSION

A second contralateral anatomic surgical resection for multiple primary lung cancer is possible, with a higher early mortality rate, but acceptable long-term survival, and should be indicated for carefully selected patients.

Genomic assessment distinguishes intrapulmonary metastases from synchronous primary lung cancers

Background

Multiple synchronous lung tumors (MSLT), particularly within a single lobe, represent a diagnostic and treatment challenge. While histologic assessment was once the only method to possibly distinguish multiple primary lung cancers, there is a growing interest in identifying unique genomic features or mutations to best characterize these processes.

Methods

In order to differentiate multiple primary lung malignancies from intrapulmonary metastases in patients with MSLT, we performed whole exome sequencing (WES) on 10 tumor samples from 4 patients with MSLT.

Results

Shared mutations between tumors from the same patient varied from 0-91%. Patient 3 shared no common mutations; however, in Patients 2 and 4, identical mutations were identified among all tumors from each patient, suggesting that the three tumors identified in Patient 3 represent separate primary lung cancers, while those of Patients 1, 2 and 4 signify hematogenous and lymphatic spread.

Conclusions

A high proportion of shared mutations between different lung tumors is likely indicative of intrapulmonary metastatic disease, while tumors with distinct genomic profiles likely represent multiple primary malignancies driven by distinct molecular events. Application of genomic profiling in the clinical setting may prove to be important to precise management of patients with MSLT.

Factors Associated With Survival in Complete Pathologic Response Non-Small Cell Lung Cancer

OBJECTIVES

There is a strong association with improved survival for patients with non-small cell lung cancer (NSCLC) who have developed a pathological complete response (pCR) after neoadjuvant therapy. A national database was used to investigate factors associated with long-term survival in this cohort of patients.

PATIENTS

Retrospective review was completed of the National Cancer Database of patients who obtained pCR and had neoadjuvant therapy for stage I to stage III NSCLC between 2004 and 2014. All patients had neoadjuvant chemotherapy with or without radiation therapy.

METHODS

Univariate and multivariable analysis was performed on factors associated with overall survival (OS), including gender, clinical stage, and nodal count. Patients were divided into 2 groups based on the Commission on Cancer-recommended median number of lymph nodes (LNs) examined: 0 to 9 LNs and ≥10 LNs. Chi-square and Wilcoxon rank-sum tests were used to compare patient, hospital, and clinical variables between groups.

RESULTS

Increased age (hazard ratio [HR] 1.02, 95% confidence interval [CI], 1.00-1.03), neoadjuvant radiation therapy (HR 1.48, 95% CI, 1.10-2.00), and pneumonectomy (HR 1.64, 95% CI, 1.22-2.22) were associated with worse survival in the 759-patient cohort. Multivariable regression demonstrated having ≥10 nodes harvested (HR 0.71, 95% CI, 0.56-0.89) was associated with improved survival as was every increase in LN harvest up to 17 LNs. No significant differences in 5-year OS were found between clinical stage I, II, and III, respectively (66.1% vs. 60.9% vs. 58.6%, P = .288).

CONCLUSION

This study shows that younger age, increasing LN harvest, female sex, the absence of neoadjuvant radiation therapy and non-pneumonectomy resections are all associated with improved OS in patients with NSCLC who have developed pCR.

Definitive Management of Presumed Synchronous Early Stage Non-Small Cell Lung Cancers: Outcomes and Utility of Stereotactic Ablative Radiation Therapy

PURPOSE

Management of synchronous early-stage non-small cell lung cancer (NSCLC) remains controversial because resection is not always feasible. This study evaluates efficacy and patterns of failure after SABR for synchronous early-stage NSCLC.

METHODS AND MATERIALS

From 2005 to 2015, patients presenting with ≥2 synchronous NSCLC tumors (T1a-T2b) and receiving SABR to ≥1 lesion were reviewed. The most common prescriptions were 50 Gy in 4 or 70 Gy in 10 fractions. Patients underwent multidisciplinary management with workup including chest computed tomography and positron emission tomography/computed tomography, plus brain imaging and endoscopic bronchial ultrasound for most patients to rule out mediastinal and distant disease. Synchronous lesions were defined as multiple ipsilateral or contralateral intrapulmonary lesions diagnosed within 6 months.

RESULTS

Of 912 patients treated with SABR for early-stage NSCLC at our institution, 82 (9%) presented with synchronous disease, with a total of 169 lesions. SABR was delivered to 142 lesions (84%), with 57 patients (69.5%) receiving SABR for all sites. Median overall survival (OS) and progression-free survival (PFS) were 5.1 and 2.7 years, respectively. At a median follow-up of 58 months, OS was 67% and 52% at 3 and 5 years, and corresponding PFS was 47% and 29%. Thirty-nine patients (48%) had progression, with 21 (26%) experiencing distant failure, and intralobar recurrence was among the first failure for 15 patients (18%). Of the 142 SABR-treated sites, these included 6 in-field (4%) and 4 marginal (3%) recurrences. There were no grade ≥3 adverse events. Among patients receiving SABR for all sites, there were no differences in OS (P = .946), PFS (P = .980), local control (P = .683), regional and distant control (P = .656), or toxicity (P = .791). On multivariable analysis, ipsilateral synchronous disease was associated with greater regional and distant failure (hazard ratio, 2.691; P = .025).

CONCLUSIONS

Synchronous NSCLC can be managed with definitive local therapy. With high control rates and favorable outcomes, SABR is an effective and feasible treatment for synchronous early-stage NSCLC.

Surgical treatment to multiple primary lung cancer patients: a systematic review and meta-analysis

BACKGROUND

As there is no consensus on the optimal surgery strategy for multiple primary lung cancer (MPLC), we conducted this study to address this issue by comparing the prognosis of MPLC patients underwent different surgical strategies including sublobar resection and the standard resection through a systemic review and meta-analysis.

METHODS

Relevant literature was obtained from three databases including PubMed, Embase and Web of Science. Inclusion and exclusion criteria were set for the screening of articles to be selected for further conduction of systemic review and meta-analysis. The HRs of OS of the sublobar group compared with standard resection group were extracted directly or calculated indirectly from included researches.

RESULTS

Ten researches published from 2000 to 2017 were included in this study, with 468 and 445 MPLC cases for the standard resection group and sublobar resection group respectively. The result suggested that OS of MPLC patients underwent sublobar resection (segmentectomy or wedge resection for at least one lesion) was comparable with those underwent standard resection approach (lobectomy or pneumonectomy for all lesions), with HR 1.07, 95% CI 0.67-1.71, p = 0.784. Further analysis found no difference in subgroups of synchronous and metachronous (from second metachronous lesion), different population region and dominant sex type.

CONCLUSIONS

This study may reveal that sublobar resection is acceptable for patients with MPLC at an early stage, because of the equivalent prognosis to the standard resection and better pulmonary function preservation. Further research is needed to validate these findings.

Unusual synchronous double primary treatment-naïve lung adenocarcinoma harboring T790M and L858R mutations in early-stage lung cancer

Background

Concurrent mutations of synchronous multiple primary non-small cell lung cancer (SMPNSCLC) is rare, and only a few cases have been reported. Herein, we present a case of early-stage SMPNSCLC with T790M and L858R mutations.

Case presentation

A 68-year-old male patient presented to the Thoracic Surgery Department due to a tumor in the right lower lung. The tumor was detected more than 5 years previously during a health examination; however, the patient ignored the problem because the clinician at that time stated that the lesion was highly likely to be benign. Chest computed topography (CT) was ordered and the images showed a well-defined tumor in the right lower lung and a faint nodular lesion over the left lower lung field. A CT-guided biopsy results showed the presence of atypical cells and positive staining of TTF-1 and CK7. Surgical intervention was performed. The right- and left-sided tumors disclosed micropapillary predominant adenocarcinoma and acinar-predominant adenocarcinoma, respectively. Both tumors were positive for TTF-1 but negative for ALK and p40. Real-time PCR analysis showed that the right-sided tumor had an epidermal growth factor receptor (EGFR) mutation presenting as point mutation T790M in exon 20, while the left-sided tumor had a point mutation L858R in exon 21 of EGFR.

Conclusions

Our patient’s case suggests that tumors resembling a benign pattern with central calcification may be misdiagnosed. Thus, early screening for lung cancer is important, and intensive efforts to make a diagnosis through surgical resection or biopsies to allow for tailored optimal treatment may be preferential for the best patient outcomes.

Impact of current versus former smoking status on the outcomes of non-metastatic non-small cell lung cancer treated with upfront surgery; findings from the National Lung Screening Trial

Objective: To evaluate the impact of current versus former smoking status on the outcomes of non-metastatic non-small cell lung cancer (NSCLC) treated with upfront surgery. Methods: This is a post-hoc analysis of patients diagnosed with NSCLC, stage I-III within the National Lung Screening Trial (NLST). Kaplan-Meier analysis was used to delineate the impact of smoking status on overall survival. Moreover, Cox regression analyses were utilized to assess factors predicting overall and lung cancer-specific survival. Results: A total of 773 patients were included in the current study. Former smokers (at the time of randomization of the NLST study) were 338 patients while current smokers were 435 patients. For overall survival, former smokers have better outcomes compared to current smokers (P = 0.023). Within multivariate Cox regression analysis, the following factors were predictive of worse overall survival: older age (P = 0.037), male gender (P = 0.022), current smoking (P = 0.022), advanced stage (P < 0.001) and preexisting stroke (P = 0.015). Likewise, the following factors were predictive of worse lung cancer-specific survival in multivariate Cox regression analysis: current smoking (P = 0.009) and advanced stage (P < 0.001). Conclusions: Among patients with early-stage NSCLC treated with upfront surgery, current smokers have worse overall and lung cancer-specific survival compared to former smokers. Expert opinion: Among patients with non-metastatic NSCLC treated with upfront surgical resection, current smokers have worse overall, lung cancer-specific and progression-free survival compared to former smokers. Smoking cessation counseling should be incorporated into management strategies of early stage NSCLC.

Multiple primary lung cancer: a rising challenge

With the use of high-resolution chest imaging system and lung cancer screening program, patients with multiple primary lung cancers (MPLCs) are becoming a growing population in clinical practice worldwide. The diagnostic criteria for MPLCs has been established and modified by three major lung cancer research institutes. However, due to the fact that the differential diagnosis between MPLCs and a recurrence, metastatic, or satellite lesion arising from the original lesion remains ambiguous and confusing, there is still insufficient evidence to support a uniform guideline. Newly developed molecular and genomic methods have the potential to better define the relationship among multiple lesions and bring the possibility of targeted therapy. Surgical resection remains the first choice for the treatment of MPLCs and detailed strategy should be carefully planned taking characteristics of the tumor and status of patients into consideration. For those who are intolerant to surgery, a new technology called stereotactic body radiation therapy (SBRT) is now an optional therapeutic strategy. Furthermore, multiple GGOs are unique MPLCs that need special attentions in the clinical practice.

Clinical analysis of 56 cases of simultaneous bilateral video-assisted thoracoscopic surgery for bilateral synchronous multiple primary lung adenocarcinoma

Background

Bilateral synchronous multiple primary lung adenocarcinoma (BSMPLA) is a rapidly increasing disease for which timely and accurate treatment is required. We describe our experience which we hope to establish optimal therapeutic options for patients with BSMPLA.

Methods

This study aimed to explore the feasibility and safety of simultaneous bilateral video-assisted thoracoscopic surgery (VATS) in 56 patients who received histological diagnoses of BSMPLA at our hospital between January 2016 and January 2018. In this retrospective analysis of clinical outcomes, we observed no serious postoperative complications or perioperative death.

Results

Four and 28 patients respectively underwent bilateral lobectomy and lobectomy with contralateral sublobar resection, whereas the remaining 24 patients underwent bilateral sublobar resection. Sublobar resection means anatomical segmentectomy or wedge resection. The mean postoperative hospital stay duration was 5.39±2.67 days. Postoperative complications comprising persistent air leakage for more than 5 days was observed in 8 (14.2%) of 56 patients. No severe postoperative complications or deaths occurred.

Conclusions

Our results suggest that simultaneous bilateral VATS is feasible, safe, and reproducible. This therapeutic strategy appears to confer considerable benefits on patients with BSMPLA.

Bilateral synchronous multiple lung nodules: Surgical experience from two cases

Synchronous multiple lung cancer (SMPLC) has been increasingly detected as a result of improved imaging techniques, though the incidence of SMPLC is rare. Surgery is currently the only treatment offering potential cure and long-term survival in patients with SMPLC, and complete resection is widely accepted as the first choice of procedure for this type. However, due to the rarity of this clinical scenario, many surgeons lack experience in surgical treatment of SMPLC. Here, we present two cases whose SMPLC was successfully managed with aggressive surgical therapy through video-assisted thoracoscopic surgery.

Surgical management of lung cancer with multiple lesions: implication of the new recommendations of the 8th edition of the TNM classification for lung cancer

The 8^th tumour, node and metastasis (TNM) revision of the staging classification for lung cancer has attempted to clarify the different properties of four distinct clinical presentations: synchronous multiple primary lung cancers; primary tumour with intrapulmonary metastases; pneumonic-type adenocarcinoma and multiple ground glass/lepidic lesions. The respective biological profiles determine different surgical strategies for each category. Accurate preoperative histological confirmation is required to identify synchronous primary tumours which should then be managed as two separate episodes within the confines of patient characteristics. Equally important is the confirmation of intrapulmonary metastasis which indicates a more conservative resection of the smaller lesion. In contrast, pneumonic-type adenocarcinoma may require larger parenchymal resection to achieve anatomical clearance but also symptom relief. Multiple subsolid lesions require a carefully planned strategy of parenchymal sparing and possible observation of less malignant abnormalities. In all the above situations careful clinical, radiological and pathological assessment is imperative to avoid one embarking on inappropriate invasive management. Either when the widespread nature of the disease renders extensive surgery futile or the relative benign or pre-malignant nature of the multiple lesions imply that the risks of surgery outweigh the prognostic benefits.

Synchronous primary lung adenocarcinomas harboring distinct MET Exon 14 splice site mutations

When a patient is found to have multiple lung tumors, distinguishing whether they represent metastatic nodules or separate primary cancers is crucial for staging and therapy. We report the case of a 79-year-old patient with two surgically resected synchronous left upper lobe adenocarcinomas initially pathologically staged as T3 (IIB), indicating adjuvant chemotherapy should be recommended. However, the tumors appeared radiographically distinct, so next-generation sequencing was performed on each nodule. Each tumor harbored a different mesenchymal-to-epithelial transition (MET) exon 14 skipping mutation, an emerging targetable mutation, suggestive of distinct clonality. While the in frame protein deletion was the same in each tumor, the nucleotide base substitutions were different. Thus, the patient was down-staged to having two separate IA tumors, spared of adjuvant chemotherapy, and routine surveillance was recommended. This case highlights the utility of using molecular analysis in diagnosing and treating multifocal lung tumors, and the process of convergent molecular evolution toward a common oncogenic driver mutation. This is the first case of multiple synchronous lung tumors each harboring a distinct MET exon 14 splice site mutation.

Coexistent Non-Small Cell Carcinoma and Small Cell Carcinoma in a Patient Presenting with Hyponatremia

Despite recent advances in screening methods, lung cancer remains the leading cause of cancer-related deaths worldwide. By the time lung cancer becomes symptomatic and patients seek treatment, it is often too advanced for curative measures. Low-dose computed tomography (CT) screening has been shown to reduce mortality in patients at high risk of lung cancer. We present a 66-year-old man with a 50-pack-year smoking history who had a right upper lobe (RUL) pulmonary nodule and left lower lobe (LLL) consolidation on a screening CT. He reported a weight loss of 45 pounds over 3 months, had recently been hospitalized for hyponatremia, and was notably cachectic. A CT of the chest showed a stable LLL mass-like consolidation and a 9 × 21 mm subsolid lesion in the RUL. Navigational bronchoscopy biopsy of the RUL lesion revealed squamous non-small cell lung cancer (NSCLC). Endobronchial ultrasound-guided transbronchial needle aspiration of the LLL lesion revealed small cell lung cancer (SCLC). The final diagnosis was a right-sided Stage I NSCLC (squamous) and a left-sided limited SCLC. The RUL NSCLC was treated with stereotactic radiation; the LLL SCLC was treated with concurrent chemotherapy and radiation. In patients with multiple lung nodules, a diagnosis of synchronous multiple primary lung cancers (MPLCs) is crucial, as inadvertent upstaging of patients with MPLC (to T3 and/or T4 tumors) can lead to erroneous staging, inaccurate prognosis, and improper treatment. Recent advances in the diagnosis of small pulmonary nodules via navigational bronchoscopy and management of these lesions dramatically affect a patient's overall prognosis.

New simple radiological criteria proposed for multiple primary lung cancers

Background

Controversies remain as to the differential diagnosis between multiple primary lung cancer (MPLC) and intrapulmonary metastasis (IM) in lung cancers. We have investigated the clinical criteria for MPLC and here propose a set of new and simple criteria from the stand point of prognosis.

Methods

A retrospective study was conducted on 588 consecutive patients with resected lung cancer of clinical Stage IA between 2009 and 2012. Multiple lung cancers (MLCs) were observed in 103 (17.5%) of the 588 patients. All main and other tumors were divided into solid tumor (ST) and non-solid tumor (non-ST). We defined Group A as MLCs having at least one non-ST and Group B as all tumors being ST. Cox's proportional hazard model was used for the multivariate analyses to investigate the preoperative prognostic factors. We divided the MLCs into MPLC and IM based on the preoperative prognostic factors, and survival was estimated by the Kaplan-Meier method.

Results

A multivariate analysis with Cox's proportional hazards model revealed that Group A independently predicted good overall survival (HR = 0.165, 95% CI: 0.041-0.672).Differences in the 3- and 5-year overall survivals between Groups A and B were statistically significant (96.3%/92.2% vs. 70.0%/60.0%, Pvalue = 0.0002).

Conclusions

We suggest that Group A, defined as the presence of at least one tumor with a ground glass opacity component and clinical N0, should be excluded from the conventional concept of multiple lung cancers based on the criteria of Martini and Melamed as it has a very good prognosis. This group would be considered to be radiological MPLC.

[Synchronous Multiple Primary Lung Cancer Dignosed by Different Phenotype-genotype: A Case Report and Literature Review]

随着低剂量螺旋计算机断层扫描（computed tomography, CT）广泛应用于早期肺癌筛查，诊断出的双肺同时多发性病变的病例数逐年增多，且大多数病例最后证实为同时性多原发肺癌（synchronous multiple primary lung cancer, SMPLC）。既往研究结果显示SMPLC的发病率约为0.2%-8%（穿刺研究结果为3.5%-14%）。目前对于MPLC的诊断，大多依据Martini-Melamed的诊断标准：SMPLC：①肺癌部位各异，彼此孤立；②组织学类型不同；③组织学类型相同时，位于不同肺段、肺叶、不同侧肺，由不同的原位癌起源，肺癌共同的淋巴引流部位无癌肿，确立诊断时无肺外转移。异时性多原发肺癌（metachronous multiple primary lung cancer, MMPLC）：①组织学类型不同；②组织学类型相同时，无瘤间期至少2年，或均由不同的原位癌起源，或第二原发癌位于不同肺叶或不同侧肺时，肺癌共同的淋巴引流部位无癌肿，确立诊断时无肺外转移。而各个肿瘤具有独特的病理形态特征为诊断MPLC的要点。此后很多学者在这条标准的基础上进行了不断的修订与丰富，包括国际肺癌研究协会（International Association for the Study of Lung Cancer, IASLC）新版肺腺癌分类及表皮生长因子受体（epidermal growth factor receptor, EGFR）、K-ras基因突变等，这些内容的增加使多原发癌灶与转移灶的鉴别诊断标准更加合理准确，也同时说明对于MPLC的各个病灶分别进行基因检测具有重要的鉴别和治疗意义。现将我院胸外科术后病理证实为不同组织亚型、不同基因型的同时性四原发肺癌患者诊治情况报道如下。

Stage I synchronous multiple primary non-small cell lung cancer: CT findings and the effect of TNM staging with the 7th and 8th editions on prognosis

Background

Studies have reported that up to 8% of non-small cell lung cancers (NSCLC) involve multiple lesions; no detailed study has assessed the prognosis of early synchronous multiple primary non-small cell lung cancer (SMPNSCLC) (T1N0M0, T2aN0M0). We aimed to assess the spiral CT manifestations of SMPNSCLC during stage I and evaluate the effect of TNM staging with the 7th and 8th editions on the prognosis.

Methods

We retrospectively analyzed the data of patients who were examined, operated, and pathologically confirmed as having NSCLC from January 1, 2009, to December 31, 2010, and were followed-up for 5 years. The number of cases with stage I SMPNSCLC and solitary primary NSCLC (SPNSCLC) was 36 and 133 as per the 7th edition TNM staging system and 34 and 111 as per the 8th edition TNM staging system, respectively. The relationship between sex, age, smoking history, emphysema, surgical procedure, pathological type, tumor location, and tumor size was evaluated between the two groups, along with the correlation between prognosis and TNM staging with the 7th and 8th editions.

Results

A total of 1,948 cases of NSCLC underwent surgery, including 36 cases of stage I SMPNSCLC (77 lesions; 1.85%) with an age of onset of 44-86 years (median age, 60 years). The tumors primarily included adenocarcinoma (93.5%), with a diameter of 0.4-4.5 cm (median, 2.3 cm). CT indicated round/oval tumors in 81.8% cases, lobulation in 79.2% cases, spiculation sign in 70.1% cases, bronchial truncation sign in 31.2% cases, and pleural indentation in 75.3% cases. Moreover, CT indicated the presence of 36 (46.8%) solid nodules and 41 (53.2%) sub-solid nodules. With the 7th edition TNM staging system, the 5-year overall survival (OS) and disease-free survival (DFS) rates for stage ISMPNSCLC were 86.1% and 72.2%, respectively, which did not significantly differ from the prognosis of 133 cases of stage I SPNSCLC (P=0.587, P=0.273). With the 8th edition TNM staging system, the 5-year OS and DFS rates for stage I SMPNSCLC were 88.2% and 73.5%, respectively, which also did not significantly differ with the prognosis of 111 cases of stage I SPNSCLC (P=0.413, P=0.235).

Conclusions

Adenocarcinoma was the main pathological type among the cases with stage I SMPNSCLC. Multiple synchronous lesions almost had the malignant characteristics of primary lung cancer, particularly the presence of single or multiple sub-solid nodules. Moreover, stage I SMPNSCLC has a similar prognosis as stage I SPNSCLC. The postoperative outcomes of stage I SMPNSCLC patients remained consistent regardless of whether the 7th or 8th edition TNM staging system was used for staging.

[Clinical and Prognosic Anylasis of 30 Cases with Double Primary Lung Cancer]

背景与目的

多原发肺癌（multiple primary lung cancer, MPLC）是一种临床中较为少见的肺癌类型，双原发肺癌（double primary lung cancer, DPLC）是其中最常见的一种，近年来由于诊疗手段的进步检出率逐渐升高。本研究总结分析了30例DPLC患者的临床资料，以期为DPLC的诊疗提供理论依据。

方法

回顾郑州大学附属肿瘤医院2010年1月-2015年12月收治的30例DPLC患者的临床资料，对临床特征及预后相关因素进行分析。

结果

30例中，同时性双原发癌（synchronous DPLC, sDPLC）占3例（3/30, 10%），异时性双原发癌（metachronous DPLC, mDPLC）占27例（27/30, 90.0%）。病灶好发于右肺上叶（20/60, 33.3%），病理类型以腺癌（25/60, 41.7%）为主，病理类型相同者（17/30, 56.7%）多于不同者（13/30, 43.3%），病理类型相同者以腺-腺（10/16, 62.5%）最常见。生存分析显示淋巴结转移（HR=4.349, 95%CI: 1.435-13.178, P=0.009）和重度吸烟史（HR=2.996, 95%CI: 1.089-8.240, P=0.034）是DPLC的不良预后因素。

结论

DPLC好发于右肺上叶，病理类型以腺癌为主，早期诊断、积极的治疗和严格的戒烟策略有望改善其预后。

Simultaneous evolutionary expansion and constraint of genomic heterogeneity in multifocal lung cancer

Recent genomic analyses have revealed substantial tumor heterogeneity across various cancers. However, it remains unclear whether and how genomic heterogeneity is constrained during tumor evolution. Here, we sequence a unique cohort of multiple synchronous lung cancers (MSLCs) to determine the relative diversity and uniformity of genetic drivers upon identical germline and environmental background. We find that each multicentric primary tumor harbors distinct oncogenic alterations, including novel mutations that are experimentally demonstrated to be functional and therapeutically targetable. However, functional studies show a strikingly constrained tumorigenic pathway underlying heterogeneous genetic variants. These results suggest that although the mutation-specific routes that cells take during oncogenesis are stochastic, genetic trajectories may be constrained by selection for functional convergence on key signaling pathways. Our findings highlight the robust evolutionary pressures that simultaneously shape the expansion and constraint of genomic diversity, a principle that holds important implications for understanding tumor evolution and optimizing therapeutic strategies.Across cancer types tumor heterogeneity has been observed, but how this relates to tumor evolution is unclear. Here, the authors sequence multiple synchronous lung cancers, highlighting the evolutionary pressures that simultaneously shape the expansion and constraint of genomic heterogeneity.

The case of synchronous occurrence of primary adenocarcinoma and squamous cell carcinoma in the same lobe of the lung

Synchronous occurrence of multiple lung cancers in the same lobe of the lung is very rare. Most of the tumors diagnosed in this way have the same histologic type. With imaging methods it is difficult to determine if the multiple lung lesions present hematogenous spread of lung cancer (or cancer from other origin) or these lesions present the second primary lung cancer. We report a rare and unusual case of synchronous occurrence of primary adenocarcinoma and squamous cell carcinoma in the same lobe of the lung. Our case demonstrates that in case of synchronous occurrence of multiple lung lesions each lesion should be sampled and histologic type of every lesion should be determined so the further treatment can be planned accordingly.

Synchronous mucinous and non-mucinous lung adenocarcinomas with different epidermal growth mutational status

In recent years, the spread of more-sensitive diagnostic methods has resulted in an increase of synchronous multiple primary lung cancer diagnosis. Nevertheless, its occurrence is still rare. Distinction between synchronous lesions from second independent primary tumors is a problem when dealing with multiple lung tumors, particularly if the histological type is the same. We present a case report of a 78-year-old female patient referred to our institution due to pneumonia. A subsequent thoracic computed tomography (CT) was performed showing two suspicious lesions, one in the right upper lobe and the other in the right inferior lobe. The CT-guided transthoracic needle biopsy of both pulmonary lesions revealed two adenocarcinomas, but with a rare combination of distinct morphologic variants, as well as different immunophenotypes and epidermal growth factor receptor (EGFR) gene status. The patient refused surgery and was submitted to stereotactic body radiation therapy (SBRT). She maintained tight follow-up and until now, she has not shown any signs of relapse or metastasis. A multidisciplinary approach with clinical, morphologic and molecular evaluation in multiple lung cancer is important to diagnosis and treatment guidance.

[Research Progress in Diagnosis and Management Strategies of Multiple Primary Lung Cancer]

原发肺癌（multiple primary lung cancer, MPLC）的发病率呈逐年上升趋势，但关于MPLC的发病机制、诊断、鉴别诊断和临床处理策略仍存在诸多争议。本综述将对目前关于MPLC的发病机制、诊断标准、鉴别诊断和处理策略方面的研究进展做一个回顾，旨在为该病的诊疗提供理论基础。

[Analysis on the Prognostic and Survival Factors of Synchronous Multiple Primary Lung Cancer]

BACKGROUND

Synchronous multiple primary lung cancer (sMPLC) is a sparse disease in the past, but there has been a gradual increase in the morbidity of sMPLC recently. However, studies on large sample have never been undertaken. The purpose of this study is to investigate the diagnosis, treatment and prognosis of sMPLC through analyzing the clinical data, and provide supports for the management of sMPLC.

METHODS

According to Martini-Melamed criteria, 357 patients were diagnosed sMPLC. The pathological staging is on the basis of the 8th edition tumor-node-metastasis (TNM) staging from International Association for the Study of Lung Cancer (IASLC).

RESULTS

There were 269 patients with double primary lung cancer, 65 patients with triple primary lung cancer and 23 patients with four or more primary lung cancer. Lesions (68.55%, 571/833) were frequently in upper lobe, especially the right upper lobe. Adenocarcinoma (95.56%, 796/833) was the mainly pathological type, followed by squamous cell carcinoma (2.40%, 20/833). The acinar predominant subtype was the main part (70.81%, 313/442) of the all adenocarcinoma specimens. Most of the lesions (68.35%, 244/357) were stage Ib or low. Among the initial lesion and the following lesions ,patients who had the same pathological type (92.72%, 331/357) were more than the different (7.28%, 26/357), of which adenocarcinoma-adenocarcinoma occupied the major proportion (99.40%, 329/331). The 3-year overall survival (OS) and 5-year overall survival were respective 91.93% and 84.37%. Multivariate analysis found that smoking history (P=0.012), the diameter of the maximum lesion (P=0.027), lymph node metastasis (P=0.015) and pleural invasion (P<0.001) were the independent risk factors for prognosis.

CONCLUSIONS

Tumours in patients with sMPLC are more frequently in the right upper lobe. Adenocarcinoma was the mainly pathological type. Smoking history, the diameter of the maximum lesion, lymph node metastasis and pleural invasion were the independent risk factors for prognosis. Early diagnosis and active operation can obtain better prognosis.

[Surgical Treatment and Prognosis for Patients with Synchronous Multiple Primary Lung Adenocarcinomas]

背景与目的

随着高分辨率计算机断层扫描（high-resolution computed tomography, HRCT）应用的普及，多原发肺癌（multiple primary lung cancers, MPLC）的检出率逐年上升，其中腺癌是最常见的病理类型。目前国内外对MPLC的研究已相对多见，但罕有单独分析同时性多原发肺腺癌（synchronous multiple primary lung adenocarcinomas, SMPLA）的报道。本研究探讨SMPLA患者的临床病理特点及预后，旨在提高对SMPLA的认识。

方法

对2012年12月-2016年7月期间我科38例临床资料保存完整的SMPLA患者进行了回顾性分析。

结果

38例SMPLA患者中，男性12例，女性26例，中位年龄为58岁（39岁-73岁）。双原发肺腺癌29例，2个病灶以上9例。病灶位于同侧26例，双侧12例。同期手术34例（包括8例患者同期行双侧手术），分期手术4例。5例患者对每个病灶分别行基因检测，结果证实不同病灶的表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变类型不完全相同。1年和3年总生存率分别为96.6%和74.2%。肿瘤直径越大（P < 0.001）、T分期越高（P=0.003）、淋巴结转移（P=0.001）、TNM分期越高（P=0.022）以及术后放、化疗（P=0.009）提示总生存预后较差。

结论

对于多发的非小细胞肺癌，不能轻易地诊断为转移癌，应考虑多原发可能。EGFR基因检测可作为鉴别多原发肺腺癌与复发转移癌的临床参考。

Genomic heterogeneity of multiple synchronous lung cancer

Multiple synchronous lung cancers (MSLCs) present a clinical dilemma as to whether individual tumours represent intrapulmonary metastases or independent tumours. In this study we analyse genomic profiles of 15 lung adenocarcinomas and one regional lymph node metastasis from 6 patients with MSLC. All 15 lung tumours demonstrate distinct genomic profiles, suggesting all are independent primary tumours, which are consistent with comprehensive histopathological assessment in 5 of the 6 patients. Lung tumours of the same individuals are no more similar to each other than are lung adenocarcinomas of different patients from TCGA cohort matched for tumour size and smoking status. Several known cancer-associated genes have different mutations in different tumours from the same patients. These findings suggest that in the context of identical constitutional genetic background and environmental exposure, different lung cancers in the same individual may have distinct genomic profiles and can be driven by distinct molecular events.

Some patients present with multiple lung tumours but it is unclear whether these are metastases or individual lesions. Here, the authors use genomics techniques to demonstrate in six patients that multiple tumours have individual genetic profiles and represent separate tumours.

Surgical treatment of synchronous multiple primary lung cancers: a retrospective analysis of 122 patients

BACKGROUND

Synchronous multiple primary lung cancers (SMPLC) become more common in clinical practice. To identify factors attributed to SMPLC treatment outcomes, we have reviewed our experiences with surgical resections of SMPLC and analyzed the treatment outcomes in this paper.

METHODS

We retrospectively analyzed clinical characteristics and treatment outcomes of patients who have been diagnosed as SMPLC and underwent surgical resection between 1990 and 2010. Based on EGFR and KRAS mutations, we identified 27 cases as SMPLC out of 50 cases, which were difficult to distinguish primary lung cancers from metastases. A total of 265 tumors from 122 patients were studied.

RESULTS

The 5-year survival rate for all patients was 40.5%. There was a significant difference in the 5-year survival between smokers and never-smokers (30.8% vs. 55.6%, P=0.011). Survival rate was also different between patients with same tumor histology and those with different tumor histology (46.9% vs. 24.8%, P=0.036). In addition, Solid nodule and pneumonectomy were associated with the worse survival (P=0.026, P=0.030). Multivariable analysis identified smoking status, stage, lymph node metastasis and pneumonectomy as significant independent predictive factors for overall survival.

CONCLUSIONS

Surgical treatment is a safe approach for patients with SMPLC; pneumonectomy should be avoided as far as possible given the poor prognosis. Mutational status of EGFR and KRAS may be advocated as a diagnostic criteria of synchronous lung cancer rather metastasis mainly in case of adenocarcinoma histology.