Lung Cancer 83 (2014) 259–264
Contents lists available at ScienceDirect
Lung Cancer journal homepage: www.elsevier.com/locate/lungcan
Clinical characteristics associated with ALK rearrangements in never-smokers with pulmonary adenocarcinoma Jong-Mu Sun a , Maruja Lira b , Kinnari Pandya b , Yoon-La Choi c , Jin Seok Ahn a , Mao Mao b , Joungho Han c , Keunchil Park a , Myung-Ju Ahn a,∗∗ , Jhingook Kim d,∗ a Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea b Pfizer Oncology, San Diego, CA, USA c Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea d Department of Thoracic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
a r t i c l e
i n f o
Article history: Received 14 August 2013 Received in revised form 17 October 2013 Accepted 11 November 2013 Keywords: Anaplastic lymphoma kinase Prevalence Epidermal growth factor receptor Prognosis Characteristic Non-small cell lung cancer ROS1
a b s t r a c t Objectives: Anaplastic lymphoma kinase (ALK) rearrangement is a validated predictive marker to define patients with non-small cell lung cancer (NSCLC) who can benefit from selective ALK inhibitors. Therefore, accurate assessment of its prevalence and clinical characteristics is increasingly important in the treatment of NSCLC. Also, this ALK rearrangement was previously reported to be more common in patients with no smoking history or those with adenocarcinoma. Patients and methods: Never-smokers with completely resected pulmonary adenocarcinoma were screened for ALK rearrangements using Nanostring’s gene expression platform. Clinicopathologic data, such as information about epidermal growth factor receptor (EGFR) and KRAS mutation status were retrospectively reviewed. Results: Of 231 tumors screened, 20 (9%) had an ALK rearrangement and all were confirmed to be positive with immunohistochemical and fluorescent in situ hybridization analysis. Of the tumors with available data on the EGFR/KRAS mutation status, EGFR and KRAS mutation rates were 64% (69/108) and 5% (5/102), respectively. Amongst the tumors that were free of EGFR and KRAS mutations, the proportion of ALK rearrangements reached up to 33%. At the time of data cut-off, total of 68 tumors were recurred. Although the recurrence rate was similar between the ALK-positive and negative groups (30% vs. 29%), there was a tendency for ALK-positive tumors to recur more frequently in the pleural space (15% vs. 5%). The fiveyear disease-free survival (61%) and overall survival rates (79%) in the ALK-positive group were similar to those in the ALK-negative group (51% and 83%, respectively). Even after excluding two patients treated with crizotinib after disease recurrence, overall survival was similar between the two groups. Conclusion: In an NSCLC subpopulation based on smoking history, histology, and EGFR and KRAS mutation status, the prevalence of ALK rearrangements is considerably high. However, ALK rearrangement status itself has no prognostic relevance in patients with completely resected NSCLC. © 2013 Elsevier Ireland Ltd. All rights reserved.
1. Introduction In 2007, anaplastic lymphoma kinase (ALK) was first identified as a driving oncogene in a subset of non-small cell lung cancer
∗ Corresponding author at: Department of Thoracic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam gu, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3483; fax: +82 2 3410 6986. ∗∗ Corresponding author at: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam gu, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3438; fax: +82 2 3410 1754. E-mail addresses: [email protected] (M.-J. Ahn), [email protected], [email protected] (J. Kim). 0169-5002/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.lungcan.2013.11.009
(NSCLC) [1]. Since then, several selective ALK inhibitors such as crizotinib, LDK378, and CH542802 have demonstrated effectiveness in patients with NSCLC harboring these ALK rearrangements [2–5]. Therefore, accurate knowledge of the prevalence and clinical characteristics of this oncogene is important in the treatment of NSCLC. The prevalence of ALK rearrangements in the general population with NSCLC is reported to range from 3% to 6% [6–12], which is very low compared to the proportion of EGFR or KRAS mutations in this group [13,14]. Several retrospective studies showed ALK rearrangements to be associated with some clinical characteristics such as younger age, a history of never smoking, and adenocarcinoma [7–9,15–17]. In line with this retrospective work, prospective
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studies enrolling patients with ALK rearrangements found most participants to be never/former smokers or to have histology of adenocarcinoma [2–5]. Although more information about the relationship between ALK rearrangements and the subsets of NSCLC is becoming available, the prognostic value of ALK rearrangements remains undetermined. Recently, a few studies have evaluated the prognostic value of ALK rearrangements in curatively resected or advanced NSCLC [9,17,18]. Since some cytotoxic chemotherapy regimens such as pemetrexed as well as selective ALK inhibitors could affect clinical outcomes of patients with ALK-positive NSCLC, the prognostic evaluation can be done more accurately in patients with curatively resected NSCLC without history of chemotherapy containing these regimens [2–5,19–21]. In addition to the presence of ALK rearrangements, the pattern of disease recurrence is an important clinical characteristic associated with prognosis. A recent study reported that ALK-positive NSCLC is more likely to metastasize to the pleura, pericardium, or liver, and the number of metastatic organs was greater than that of ALK-negative NSCLC [22]. This suggests that a tumor with an ALK rearrangement may have specific, predictable biologic behavior. In the present study, we evaluated the prevalence of ALK rearrangements in a selective group of the NSCLC population, clinically enriched for relevant predictive factors. We also evaluated the pattern of disease recurrence and the prognosis of patients with ALK-positive NSCLC that has been completely resected.
2+ or 3+ were regarded as ALK-positivity by the IHC method. For the FISH analysis, we used a probe specific to the ALK locus (Vysis LSI ALK dual-color, break-apart rearrangement probe; Abbott Molecular, Abbott Park, IL, USA), and a positive FISH result for ALK rearrangement was defined as >15% of tumor cells with a split signal. In the present study, information about the EGFR and KRAS mutation status was acquired from medical records. The mutational analyses were performed by directional sequencing of polymerase chain reaction (PCR) fragments amplified with genomic DNA from paraffin-embedded tissue. 2.3. Statistical analysis To compare the prevalence of ALK rearrangements according to our clinical characteristics of interest, we used Chi-square tests or Student’s t-tests wherever appropriate. The Kaplan–Meier method was used to plot the disease-free survival (DFS) or overall survival (OS) curves, and the log rank test was used to compare the differences between subgroups. The Cox proportional hazards model was used to estimate the hazard ratio (HR) for DFS. Statistical analyses were performed using SPSS 19.0 (SPSS Inc., Chicago, IL, USA), and statistical significance was considered at p < 0.05. 3. Results 3.1. Characteristics of patients with ALK rearrangements
2. Patients and methods 2.1. Patient cohort Among the patients with NSCLC who underwent complete resection at the Samsung Medical Center (Seoul, Korea) between September 2007 and July 2012, 231 never-smokers with pulmonary adenocarcinoma were screened for the presence of the ALK gene rearrangement. In the process of screening with Nanostring’s method, we also searched the ROS1 gene rearrangement to evaluate its prevalence rate. Clinical data extracted from the medical records included age, sex, tumor stage, neoadjuvant or adjuvant chemotherapy, epidermal growth factor receptor (EGFR) or KRAS mutation status, the sites of initial disease recurrence, and the date of disease recurrence or death. Tumor stage was defined according to the seventh edition of the American Joint Committee on cancer staging system [23]. Never-smokers were defined as individuals who had a lifetime smoking exposure of 60 years 114 ≤60 years Tumor stage 94 IA IB 58 IIA 23 IIB 8 45 IIIA 3 IIIB EGFR mutation 69 Positive 39 Negative 123 Unknown KRAS mutation 5 Positive Negative 102 124 Unknown (Neo) adjuvant chemotherapy in stage II/III (n = 79) 60 Yes 19 No
p value
No. positive
No. negative
Proportion positive
20
211
9%
5 15
29 182
15% 8%
57 8 12
61 109 102
7% 11%
2 8 4 1 5 0
82 50 19 7 40 3
2% 14% 17% 13% 11% 0%
0 12 8
69 27 115
0% 31% 7%
0 12 8
5 90 116
0% 12% 6%
9 1
51 18
15% 5%
0.17
0.02 0.32 0.08
60 years ≤60 years Tumor stage 1A 1B 2A 2B 3A 3B ALK rearrangement Positive Negative EGFR mutation (n = 108) Positive Negative KRAS mutation (n = 107) Positive Negative
231
52
197 34
56 29
117 114
42 62
94 58 23 8 45 3
75 58 37 35 20 33
20 211
61 51
69 39
39 40
5 102
30 40
p
5-year OS rate (%) 0.07
0.001 88 62
0.009
0.017 94 73
Contents lists available at ScienceDirect
Lung Cancer journal homepage: www.elsevier.com/locate/lungcan
Clinical characteristics associated with ALK rearrangements in never-smokers with pulmonary adenocarcinoma Jong-Mu Sun a , Maruja Lira b , Kinnari Pandya b , Yoon-La Choi c , Jin Seok Ahn a , Mao Mao b , Joungho Han c , Keunchil Park a , Myung-Ju Ahn a,∗∗ , Jhingook Kim d,∗ a Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea b Pfizer Oncology, San Diego, CA, USA c Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea d Department of Thoracic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
a r t i c l e
i n f o
Article history: Received 14 August 2013 Received in revised form 17 October 2013 Accepted 11 November 2013 Keywords: Anaplastic lymphoma kinase Prevalence Epidermal growth factor receptor Prognosis Characteristic Non-small cell lung cancer ROS1
a b s t r a c t Objectives: Anaplastic lymphoma kinase (ALK) rearrangement is a validated predictive marker to define patients with non-small cell lung cancer (NSCLC) who can benefit from selective ALK inhibitors. Therefore, accurate assessment of its prevalence and clinical characteristics is increasingly important in the treatment of NSCLC. Also, this ALK rearrangement was previously reported to be more common in patients with no smoking history or those with adenocarcinoma. Patients and methods: Never-smokers with completely resected pulmonary adenocarcinoma were screened for ALK rearrangements using Nanostring’s gene expression platform. Clinicopathologic data, such as information about epidermal growth factor receptor (EGFR) and KRAS mutation status were retrospectively reviewed. Results: Of 231 tumors screened, 20 (9%) had an ALK rearrangement and all were confirmed to be positive with immunohistochemical and fluorescent in situ hybridization analysis. Of the tumors with available data on the EGFR/KRAS mutation status, EGFR and KRAS mutation rates were 64% (69/108) and 5% (5/102), respectively. Amongst the tumors that were free of EGFR and KRAS mutations, the proportion of ALK rearrangements reached up to 33%. At the time of data cut-off, total of 68 tumors were recurred. Although the recurrence rate was similar between the ALK-positive and negative groups (30% vs. 29%), there was a tendency for ALK-positive tumors to recur more frequently in the pleural space (15% vs. 5%). The fiveyear disease-free survival (61%) and overall survival rates (79%) in the ALK-positive group were similar to those in the ALK-negative group (51% and 83%, respectively). Even after excluding two patients treated with crizotinib after disease recurrence, overall survival was similar between the two groups. Conclusion: In an NSCLC subpopulation based on smoking history, histology, and EGFR and KRAS mutation status, the prevalence of ALK rearrangements is considerably high. However, ALK rearrangement status itself has no prognostic relevance in patients with completely resected NSCLC. © 2013 Elsevier Ireland Ltd. All rights reserved.
1. Introduction In 2007, anaplastic lymphoma kinase (ALK) was first identified as a driving oncogene in a subset of non-small cell lung cancer
∗ Corresponding author at: Department of Thoracic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam gu, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3483; fax: +82 2 3410 6986. ∗∗ Corresponding author at: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam gu, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3438; fax: +82 2 3410 1754. E-mail addresses: [email protected] (M.-J. Ahn), [email protected], [email protected] (J. Kim). 0169-5002/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.lungcan.2013.11.009
(NSCLC) [1]. Since then, several selective ALK inhibitors such as crizotinib, LDK378, and CH542802 have demonstrated effectiveness in patients with NSCLC harboring these ALK rearrangements [2–5]. Therefore, accurate knowledge of the prevalence and clinical characteristics of this oncogene is important in the treatment of NSCLC. The prevalence of ALK rearrangements in the general population with NSCLC is reported to range from 3% to 6% [6–12], which is very low compared to the proportion of EGFR or KRAS mutations in this group [13,14]. Several retrospective studies showed ALK rearrangements to be associated with some clinical characteristics such as younger age, a history of never smoking, and adenocarcinoma [7–9,15–17]. In line with this retrospective work, prospective
260
J.-M. Sun et al. / Lung Cancer 83 (2014) 259–264
studies enrolling patients with ALK rearrangements found most participants to be never/former smokers or to have histology of adenocarcinoma [2–5]. Although more information about the relationship between ALK rearrangements and the subsets of NSCLC is becoming available, the prognostic value of ALK rearrangements remains undetermined. Recently, a few studies have evaluated the prognostic value of ALK rearrangements in curatively resected or advanced NSCLC [9,17,18]. Since some cytotoxic chemotherapy regimens such as pemetrexed as well as selective ALK inhibitors could affect clinical outcomes of patients with ALK-positive NSCLC, the prognostic evaluation can be done more accurately in patients with curatively resected NSCLC without history of chemotherapy containing these regimens [2–5,19–21]. In addition to the presence of ALK rearrangements, the pattern of disease recurrence is an important clinical characteristic associated with prognosis. A recent study reported that ALK-positive NSCLC is more likely to metastasize to the pleura, pericardium, or liver, and the number of metastatic organs was greater than that of ALK-negative NSCLC [22]. This suggests that a tumor with an ALK rearrangement may have specific, predictable biologic behavior. In the present study, we evaluated the prevalence of ALK rearrangements in a selective group of the NSCLC population, clinically enriched for relevant predictive factors. We also evaluated the pattern of disease recurrence and the prognosis of patients with ALK-positive NSCLC that has been completely resected.
2+ or 3+ were regarded as ALK-positivity by the IHC method. For the FISH analysis, we used a probe specific to the ALK locus (Vysis LSI ALK dual-color, break-apart rearrangement probe; Abbott Molecular, Abbott Park, IL, USA), and a positive FISH result for ALK rearrangement was defined as >15% of tumor cells with a split signal. In the present study, information about the EGFR and KRAS mutation status was acquired from medical records. The mutational analyses were performed by directional sequencing of polymerase chain reaction (PCR) fragments amplified with genomic DNA from paraffin-embedded tissue. 2.3. Statistical analysis To compare the prevalence of ALK rearrangements according to our clinical characteristics of interest, we used Chi-square tests or Student’s t-tests wherever appropriate. The Kaplan–Meier method was used to plot the disease-free survival (DFS) or overall survival (OS) curves, and the log rank test was used to compare the differences between subgroups. The Cox proportional hazards model was used to estimate the hazard ratio (HR) for DFS. Statistical analyses were performed using SPSS 19.0 (SPSS Inc., Chicago, IL, USA), and statistical significance was considered at p < 0.05. 3. Results 3.1. Characteristics of patients with ALK rearrangements
2. Patients and methods 2.1. Patient cohort Among the patients with NSCLC who underwent complete resection at the Samsung Medical Center (Seoul, Korea) between September 2007 and July 2012, 231 never-smokers with pulmonary adenocarcinoma were screened for the presence of the ALK gene rearrangement. In the process of screening with Nanostring’s method, we also searched the ROS1 gene rearrangement to evaluate its prevalence rate. Clinical data extracted from the medical records included age, sex, tumor stage, neoadjuvant or adjuvant chemotherapy, epidermal growth factor receptor (EGFR) or KRAS mutation status, the sites of initial disease recurrence, and the date of disease recurrence or death. Tumor stage was defined according to the seventh edition of the American Joint Committee on cancer staging system [23]. Never-smokers were defined as individuals who had a lifetime smoking exposure of 60 years 114 ≤60 years Tumor stage 94 IA IB 58 IIA 23 IIB 8 45 IIIA 3 IIIB EGFR mutation 69 Positive 39 Negative 123 Unknown KRAS mutation 5 Positive Negative 102 124 Unknown (Neo) adjuvant chemotherapy in stage II/III (n = 79) 60 Yes 19 No
p value
No. positive
No. negative
Proportion positive
20
211
9%
5 15
29 182
15% 8%
57 8 12
61 109 102
7% 11%
2 8 4 1 5 0
82 50 19 7 40 3
2% 14% 17% 13% 11% 0%
0 12 8
69 27 115
0% 31% 7%
0 12 8
5 90 116
0% 12% 6%
9 1
51 18
15% 5%
0.17
0.02 0.32 0.08
60 years ≤60 years Tumor stage 1A 1B 2A 2B 3A 3B ALK rearrangement Positive Negative EGFR mutation (n = 108) Positive Negative KRAS mutation (n = 107) Positive Negative
231
52
197 34
56 29
117 114
42 62
94 58 23 8 45 3
75 58 37 35 20 33
20 211
61 51
69 39
39 40
5 102
30 40
p
5-year OS rate (%) 0.07
0.001 88 62
0.009
0.017 94 73
