Abstract P1-16-10: Treatment patterns and outcomes of different subtypes of metastatic breast cancer patients in a Swedish real world setting with a focus on HER2-/HR+ subtype

Introduction: The most frequent molecular subtype of metastatic breast cancer (MBC) is the HER2-/HR+ subtype. While there are several treatments available for HER2-/HR+ MBC patients, there is limited knowledge about how patients are treated in a real world setting. In this retrospective study, the aim was to describe the duration of four initial treatment lines, treatment patterns and outcomes in MBC subtypes, with a focus on the HER2-/HR+ subtype.

Methods: The population is a cohort of 370 MBC patients diagnosed during '09-´16 in Uppsala County, Sweden. Data were collected from a regional breast cancer registry which included medical records. The subtypes were HER2-/HR+(59%); HER2+/HR+(12%); HER2+/HR-(7%) and HER2-/HR-(12%) based on immunohistochemistry (IHC) and in situ hybridization (ISH) tests, 11% of records had missing data on subtypes. Kaplan-Meier estimates were used to model duration of treatment line, progression-free survival (PFS) and overall survival (OS). Cox proportional hazard models were used to test the association, expressed in hazard ratios (HR), between the subtypes and PFS and OS.

Results: The median PFS and OS of HER2-/HR+ subtype were 10.6 and 36.7 months, respectively. Compared to the HER2-/HR+ patients, a statistically significant difference was found for HER2-/HR- patients in terms of PFS (HR: 2.1; p-value<0.001) and OS (HR: 3.6; p-value<0.01), indicating a worse prognosis. HER2+/HR+ and HER2+/HR-patients had similar PFS and OS results to HER2-/HR+ patients.

A statistically significant association was found between HR+ expression and OS (HR: 0.5; p-value<0.001) and not between HER2+ expression and OS (HR: 1.0; p-value 0.79 ).

The median duration of treatment decreased with increasing treatment lines; HER2-/HR+ patients' first-line treatment lasted 7.2, second-line 5.5, third-line 4.7 and fourth-line 4.4 months. The proportion of chemotherapy increased with the number of treatment lines: 32%, 38%, 46% and 59% for first to fourth line, respectively.

The ten most used drugs of HER2-/HR+ cohort are summarized in Table 1. In total, endocrine therapy was given during 66% of the total treatment duration.

Table 1:Ten most used drugs of HER2-/HR+N=197Patient-years (sum of treatment durations)Relative frequency of patient-years (%). Total=511 yearsLetrozole19037Tamoxifen5611Capecitabine5511Exemestane438Fulvestrant316FEC245Paclitaxel235Docetaxel143Vinorelbine112Everolimus92

Conclusion: In this retrospective study of MBC patients, the expression of HR showed an individual positive impact of OS with a 50% reduction in hazards. In our cohort only the prognosis of HER2-/HR- patients were significantly worsened both in terms of PFS and OS compared to HER2-/HR+ subtype. In the analysis of HER2-/HR+ subtype, letrozole was the most durable therapy, used 37% of total treatment time. The most used chemotherapy was capecitabine, used in 11% of the treatment time.

Citation Format: Lindman H, Szilcz M, Freilich J, Carlqvist P, Vertuani S, Anell B, Holm B. Treatment patterns and outcomes of different subtypes of metastatic breast cancer patients in a Swedish real world setting with a focus on HER2-/HR+ subtype [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-16-10.

Single-institution retrospective comparison of preoperative versus definitive chemoradiotherapy for adenocarcinoma of the esophagus

PURPOSE

We sought to determine the impact of esophagectomy on survival in patients with adenocarcinoma of the esophagus cancer after chemoradiotherapy (CRT).

METHODS

A database of esophageal cancer was queried for nonmetastatic patients with adenocarcinoma treated between 2000 and 2011 with CRT. Overall survival (OS) and recurrence-free survival (RFS) curves were calculated according to the Kaplan-Meier method and log-rank analysis. Multivariate analysis was performed by the Cox proportional hazard model.

RESULTS

We identified 154 patients (60 without surgery; 94 with surgery) who were included in the analysis. The only differences between the 2 groups were more advanced disease stage, improved performance status, and younger age in the surgery group. Patients undergoing surgery had significantly higher survival. Median and 5-year OS for surgical patients were 4.1 years and 43.6 %, versus 1.9 years and 35.6 % for nonsurgical patients (p = 0.007). Multivariate analysis for OS and RFS revealed that factors associated with increased survival were surgical resection, tumor length < 5 cm, male gender, and lower stage. Age, tumor location, radiation dose/technique, and induction chemotherapy were not prognostic. There was a trend toward improved survival on univariate analysis (p = 0.10) and multivariate analysis (p = 0.063) for surgical patients compared to nonsurgical patients who were healthy enough for surgery before CRT (n = 38), and no difference in OS in nonsurgical patients healthy enough for surgery after CRT (n = 22).

CONCLUSION

Esophagectomy after CRT is associated with improved survival in patients with adenocarcinoma after CRT. Trimodal therapy should continue to remain the standard of care for esophageal adenocarcinoma.

Comparative outcomes for three-dimensional conformal versus intensity-modulated radiation therapy for esophageal cancer

Emerging data suggests a benefit for using intensity modulated radiation therapy (IMRT) for the management of esophageal cancer. We retrospectively reviewed patients treated at our institution who received definitive or preoperative chemoradiation with either IMRT or 3D conformal radiation therapy (3DCRT) between October 2000 and January 2012. Kaplan Meier analysis and the Cox proportional hazard model were used to evaluate survival outcomes. We evaluated a total of 232 patients (138 IMRT, 94 3DCRT) who received a median dose of 50.4 Gy (range, 44-64.8) to gross disease. Median follow up for all patients, IMRT patients alone, and 3DCRT patients alone was 18.5 (range, 2.5-124.2), 16.5 (range, 3-59), and 25.9 months (range, 2.5-124.2), respectively. We observed no significant difference based on radiation technique (3DCRT vs. IMRT) with respect to median overall survival (OS) (median 29 vs. 32 months; P = 0.74) or median relapse free survival (median 20 vs. 25 months; P = 0.66). On multivariable analysis (MVA), surgical resection resulted in improved OS (HR 0.444; P < 0.0001). Superior OS was also associated on MVA with stage I/II disease (HR 0.523; P = 0.010) and tumor length ≤5 cm (HR 0.567; P = 0.006). IMRT was also associated on univariate analysis with a significant decrease in acute weight loss (mean 6% + 4.3% vs 9% + 7.4%, P = 0.012) and on MVA with a decrease in objective grade ≥3 toxicity, defined as any hospitalization, feeding tube, or >20% weight loss (OR 0.51; P = 0.050). Our data suggest that while IMRT-based chemoradiation for esophageal cancer does not impact survival there was significantly less toxicity. In the IMRT group there was significant decrease in weight loss and grade ≥3 toxicity compared to 3DCRT.

Outcomes of adjuvant radiotherapy and lymph node dissection in elderly patients with pancreatic cancer treated with surgery and chemotherapy

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Background: To determine the effects of postoperative radiation therapy (PORT) and lymph node resection (LNR) on survival in patients age ≥ 70 with pancreatic cancer treated with surgery and chemotherapy. Methods: An analysis of patients with surgically resected pancreatic cancer who received chemotherapy from the SEER database from 2004-2008 was performed to determine association of PORT and LNR on survival. Survival curves were calculated according to the Kaplan-Meier method and log-rank analysis. Multivariate analysis (MVA) was performed by the Cox proportional hazard model. Results: We identified 961 patients who met inclusion criteria. The only significant difference between PORT patients and no PORT patients was age, median 75 and 76 years, respectively (p=0.007). Overall survival (OS) in PORT versus no PORT was not statistically different in the whole cohort (p=0.064), N0 (p=0.803) or N1 (p=0.0501). On univariate analysis (UVA) there was increased OS in patients with lower T stage (p<0.001), N0 status (p<0.001), lower AJCC stage (p<0.001) and lower grade (p<0.001). No OS difference was seen based on gender, location, or PORT. There was no difference in OS based on number of lymph nodes removed in all patients (p=0.74), N0 (p=0.59), and N1 (p=0.07). MVA for all patients revealed higher T stage, N1, and high grade were prognostic for worse mortality, while there was a trend for decreased mortality with PORT (p=0.052). In N0 patients, increased T-stage and grade were prognostic for worse survival, while PORT and number of lymph nodes removed were not. In N1 patients, higher T-stage and grade were prognostic for increased mortality, while increasing number of lymph nodes removed was associated with decreased mortality. PORT trended towards improved survival in N1 patients (p=0.06). Age, gender and tumor location were not prognostic for survival. Conclusions: Adjuvant radiation therapy and number of lymph nodes removed in patients age ≥70 does not seem to correlate with increased OS in surgically resected pancreatic cancer treated with chemotherapy. Future clinical trials will need to address age as a stratification factor for pancreatic cancer in the adjuvant setting.

Survival impact of esophagectomy after chemoradiation for adenocarcinoma of the esophagus

132

Background: To determine the impact of esophagectomy on survival in patients with adenocarcinoma (AC) of the esophagus cancer after chemoradiation (CRT). Methods: A database of esophageal cancer was queried for nonmetastatic patients with AC treated between 2000 and 2011 with CRT. Overall survival (OS) and recurrence-free survival (RFS) curves were calculated according to the Kaplan-Meier method and log-rank analysis. Multivariate analysis (MVA) was performed by the Cox proportional hazard model. Results: We identified 154 patients (60 without surgery; 94 with surgery) who were included in the analysis. The only differences between the 2 groups were more advanced stage and younger age in the surgery group. Patients undergoing surgery had significantly higher survival. Median and 5 year OS for surgical patients was 4.1 years and 43.6% versus 1.9 years and 35.6% for non surgical patients (p=0.007). MVA for OS and DFS revealed that factors associated with increased survival were surgical resection, tumor length <5 cm, male gender, and lower stage. Age, tumor location, radiation dose/technique, and induction chemotherapy were not prognostic. There was a trend towards improved survival on univariate analysis (p=0.10) and MVA (p=0.063) for surgery patients compared to non-surgical patients who were healthy enough for surgery pre-CRT (n=38), and no difference in OS in nonsurgical patients healthy enough for surgery post-CRT (n=22). Conclusions: Esophagectomy after CRT dramatically improves survival in patients with AC after CRT. Trimodality therapy should continue to remain the standard of care for esophageal AC. However, surgery should be performed at high volume centers.

A comparison of outcomes for 3D conformal versus intensity modulated radiation therapy in postoperative gastric cancer

139

Background: Postoperative radiation therapy (RT) for gastric cancer results in increased survival. Treatment planning studies have demonstrated improved target coverage and normal tissue sparing with intensity modulated RT (IMRT) versus 3D conformal radiotherapy (3DCRT). The purpose of this study was to compare outcomes of gastric cancer patients treated with IMRT vs 3DCRT. Methods: An IRB approved database was queried for all postoperative gastric cancer patients who received adjuvant chemoradiation with either 3DCRT or IMRT between 2000 and 2012. The primary endpoints were survival and toxicity. Overall (OS) and disease-free survival (DFS) were calculated with Kaplan-Meier analysis and multivariate analysis (MVA) was performed using a Cox proportional hazard ratio model. Results: We identified 39 patients (23 3DCRT, 16 IMRT). Median followup for all patients, 3DCRT patients, and IMRT patients was 16.2, 24.6, and 14.4 months, respectively. The only difference between groups noted was the presence of more positive lymph nodes (p=0.015) and higher N stage (0.012) in the 3DCRT group. There was no difference in OS or DFS on univariate or MVA. The median OS was 27.6 for the IMRT patients versus 27.4 months in the 3DCRT patients (p=0.63). In patients treated with IMRT we observed a nonsignificant decrease in grade ≥3 toxicity (25% vs. 39%; p = 0.50), any hospitalization (25% vs. 30%; p = 0.74), and median weight change (7% vs. 9%; p=0.62). On MVA for grade >3 toxicity age, gender, stage, type of surgery, pre-operative chemotherapy, number of lymph nodes removed and radiation technique were all nonsignificant. The hazard ratio for radiation technique was 0.600 (95% CI 0.118-3.042; p value=0.537). Conclusions: Our data did not demonstrate differences in OS or DFS but did show a decrease in toxicity. Caution should be taken given small sample size and short follow up in IMRT patients. Comparative outcomes for these two techniques therefore warrant continued exploration.

Comparative outcomes for 3D conformal versus intensity modulated radiation therapy for esophageal cancer

76

Background: Emerging data suggests a benefit for using intensity modulated radiation therapy (IMRT) for the management of esophageal cancer. Methods: We retrospectively reviewed patients treated at our institution who received definitive or preoperative chemoradiation with either IMRT or 3D conformal radiation therapy (3DCRT) between October 2000 and January 2012. Kaplan Meier analysis and the Cox proportional hazard model were used to evaluate survival outcomes. Results: We evaluated a total of 232 patients (138 IMRT, 94 3DCRT) who received a median dose of 50.4 Gy (range, 44-64.8) to gross disease. Median follow up for all patients, IMRT patients alone, and 3DCRT patients alone was 18.5 (range, 2.5-124.2), 16.5 (range, 3-59), and 25.9 months (range, 2.5-124.2), respectively. We observed no significant difference based on radiation technique (3DCRT vs. IMRT) with respect to median overall survival (OS) (29 vs. 32 months; p=0.78) or median relapse free survival (RFS) (20 vs. 25 months; p=0.74). On multivariable analysis (MVA), not undergoing surgical resection resulted in worse OS (HR 2.255; p <0.0001) and RFS (HR 1.893; p<0.0001). Superior OS was associated on MVA with stage I/II disease (HR 0.523; p=0.010) and tumor length ≤5 cm (HR 0.567; p=0.006). Improved RFS on MVA was associated with stage I/II disease (HR 0.663; p=0.070), tumor length ≤5 cm (HR 0.611; p=0.011), adenocarcinoma histology (HR 0.532; p=0.055), and 3DCRT(HR 0.524; p=0.002). IMRT was also associated on univariate analysis with a significant decrease in acute weight loss (mean 6%+4.3% vs 9%+7.4%, p=0.0001) and on MVA with a decrease in objective grade ≥ 3 toxicity, defined as any hospitalization, feeding tube, or >20% weight loss (OR 0.51; p=0.050). Conclusions: Our data suggest that while IMRT-based chemoradiation for esophageal cancer does not impact survival there was significantly less toxicity. In the IMRT group there was significant decrease in weight loss and grade ≥3 toxicity compared to 3DCRT.

Intensity-modulated radiation therapy versus 3D conformal radiation therapy for squamous cell carcinoma of the anal canal

494

Background: The emergence of intensity-modulated radiation therapy (IMRT) in the treatment of anal cancer has dramatically lowered the incidence of severe toxicity while maintaining excellent long-term outcomes. We compared our institutional experience using 3D conformal radiation therapy (3DCRT) versus IMRT for anal cancer. Methods: We performed a single-institution retrospective review of all non-metastatic squamous cell carcinoma anal cancer patients treated between 2000-2011 using definitive chemoradiation with curative intent. Results: This study included 89 consecutive anal cancer patients (37 3DCRT, 52 IMRT). Median follow-up for all patients, IMRT patients alone, and CRT patients alone was 26.5 months (range, 3.5-133.6), 20 months (range, 3.5-125.5), and 61.9 months (range, 7.6-133.6), respectively. Three-year overall survival (OS), progression free survival (PFS), locoregional control (LRC), and colostomy free survival (CFS) were 91.1%, 82.3%, 90.8%, and 91.3% in the IMRT cohort and 86.1%, 72.5%, 91.9%, and 93.7% for the 3DCRT patients (all p>0.1). More patients in the 3DCRT group required a treatment break (11 vs. 4; p=0.006), although the difference in median treatment break duration was not significant (12.2 vs. 8.0 days; p=0.35). Survival outcomes did not differ based on whether a treatment break was required (all p>0.1). Acute grade ≥3 non-hematologic toxicity was significantly decreased in the IMRT cohort (21.1 vs. 59.5%; p<0.0001). Acute grade ≥3 skin toxicity was significantly worse in the 3DCRT group (p<0.0001) while an improvement in late grade ≥3 GI toxicity was observed in the IMRT patients (p=0.012). Conclusions: This is the largest retrospective review comparing 3DCRT and IMRT for definitive treatment of anal cancer. In contrast to previously published data, this study demonstrates that while long-term outcomes do not significantly differ based on RT technique, a marked decrease in adverse effects and the need for a treatment break can be achieved using IMRT.

Survival in patients with esophageal cancer treated with surgery after chemoradiotherapy

98

Background: Chemoradiotherapy (CRT) followed by surgical resection is the standard of care for treating advanced esophageal cancer. However, the role of surgery has come into question in recent studies. The purpose of this study is to compare outcomes of patients treated with CRT with or without surgery. Methods: An IRB-approved database was queried to identify esophageal cancer patients treated with CRT with or without surgical resection between 2000 and 2011. Overall survival (OS) and disease-free survival (DFS) were calculated by the Kaplan-Meier method and log-rank analysis. Multivariate analysis for OS and DFS were calculated with a Cox proportional hazard ratio model. Results: We identified 232 patients treated with CRT (122 without surgery, 110 with surgery). Surgery was associated with a significant increase in OS and DFS. Median and 5 year OS for surgical versus nonsurgical patients was 42.2 months, and 42.3% versus 20.4 months and 29%, respectively (p = 0.0003). Median and 5 year DFS for surgical versus nonsurgical patients was 16.8 months and 29% versus 8.4 months and 22.8% (p < 0.001). MVA for OS revealed that lower stage (p = 0.0098), tumor length <5 cm (p = 0.0059), and surgery (p<0.0001) were prognostic for significantly decreased mortality, while age, gender, histology, tumor location, radiation dose, and radiation technique were not prognostic. MVA for DFS showed that tumor length <5 cm (p = 0.0112), radiation technique (p = 0.0023), and surgery (p = 0.0007) were prognostic for significantly decrease mortality, while lower stage (p = 0.069) and squamous histology (p = 0.055) were trending for decreased mortality. Age, gender, radiation dose, and tumor location were not prognostic for DFS. Conclusions: Surgery after CRT is strongly associated with increased OS and DFS in our esophageal cancer patient population. While we highly recommend surgical resection as part of trimodality treatment, it should only be performed in high volume centers. Longer followup in the already conducted randomized trials involving squamous cell carcinomas are needed to better qualify the initial negative results and randomized trials are need to address the role of surgery for adenocarcinomas.

The impact of the size of nodal metastases on recurrence risk in breast cancer patients with 1-3 positive axillary nodes after mastectomy

PURPOSE

Use of postmastectomy radiation therapy (PMRT) in breast cancer patients with 1-3 positive nodes is controversial. The objective of this study was to determine whether the size of nodal metastases in this subset could predict who would benefit from PMRT.

METHODS AND MATERIALS

We analyzed 250 breast cancer patients with 1-3 positive nodes after mastectomy treated with contemporary surgery and systemic therapy at our institution. Of these patients, 204 did not receive PMRT and 46 did receive PMRT. Local and regional recurrence risks were stratified by the size of the largest nodal metastasis measured as less than or equal to 5 mm or greater than 5 mm.

RESULTS

The median follow-up was 65.6 months. In the whole group, regional recurrences occurred in 2% of patients in whom the largest nodal metastasis measured 5 mm or less vs 6% for those with metastases measuring greater than 5 mm. For non-irradiated patients only, regional recurrence rates were 2% and 9%, respectively. Those with a maximal nodal size greater than 5 mm had a significantly higher cumulative incidence of regional recurrence (P=.013). The 5-year cumulative incidence of a regional recurrence in the non-irradiated group was 2.7% (95% confidence interval [CI], 0.7%-7.2%) for maximal metastasis size of 5 mm or less, 6.9% (95% CI, 1.7%-17.3%) for metastasis size greater than 5 mm, and 16% (95% CI, 3.4%-36.8%) for metastasis size greater than 10 mm. The impact of the maximal nodal size on regional recurrences became insignificant in the multivariable model.

CONCLUSIONS

In patients with 1-3 positive lymph nodes undergoing mastectomy without radiation, nodal metastasis greater than 5 mm was associated with regional recurrence after mastectomy, but its effect was modified by other factors (such as tumor stage). The size of the largest nodal metastasis may be useful to identify high-risk patients who may benefit from radiation therapy after mastectomy.

Influence of promethazine on symptom-therapy scores for nausea during patient-controlled analgesia with morphine

We assessed whether adding promethazine to the syringe containing morphine for patient-controlled analgesia (PCA) decreases nausea after gynecologic surgery. Patients were assigned randomly to receive PCA (morphine 1.5 mg, 6-min lockout interval) with or without promethazine (0.625 mg/PCA dose, providing an average of 17.6 mg/24 h). Assessments included a visual analogue scale (VAS) for nausea (0 = none, 10 = worst possible) at scheduled times, rescue therapy requirements, and a maximum symptom-therapy score that provided an aggregate assessment of nausea intensity, duration, and response to rescue therapy (0 = no nausea; 1 = mild; 2 = moderate, requiring droperidol; 3 = severe or persistent, requiring droperidol; 4 = requiring droperidol+transdermal scopolamine; 5 = unrelieved). Nausea scores on the visual analogue scale at 2, 6, 8, and 24 h and use of rescue droperidol identified no significant differences between the groups. However, symptom-therapy scores differed significantly, with median values of 0 and 2, respectively, for the promethazine-treated and control groups. We conclude that simultaneous titration of morphine and promethazine decreases nausea associated with PCA therapy; the difference may best be appreciated with use of the combined symptom-therapy score.