Optimal Surgical Management for Occult Breast Carcinoma: A Meta-analysis

Axilla Management in Breast Cancer Surgery: Brief Review and Current Practice Recommendations

The diagnostic and therapeutic approach to the axilla in breast cancer patients has changed significantly over the past 30 years, with the replacement of complete axillary lymph node dissection practices by less invasive approaches. Reference is made to clinical findings that have led to practical treatment recommendations and are paving the way to new levels of de-escalation in breast cancer surgery.

Shifting from axillary dissection to targeted axillary surgery after neoadjuvant treatment: the evolving management of occult breast cancer in a monoinstitutional series of 114 patients

PURPOSE

The use of neoadjuvant systemic therapy for primary breast cancer can achieve tumor shrinkage, enabling less invasive surgical treatments, such as breast-conserving surgery instead of mastectomy, and sentinel node biopsy instead of axillary dissection. In recent years, an increasing number of studies have explored the use of primary systemic therapy for occult breast cancer with axillary presentation. These studies suggest that a more conservative approach, involving targeted axillary surgery could be cautiously proposed for occult breast cancer after neoadjuvant chemotherapy in selected patients. In cases where a complete pathological response in the lymph nodes is achieved, there may also be the possibility to omit radiotherapy.

METHODS

We retrospectively reviewed surgical interventions for carcinoma of unknown primary (CUP) syndrome with axillary presentation at the European Institute of Oncology from April 2004 to October 2022. Demographic and clinicopathological characteristics of the patients were collected and follow-up information has been updated.

RESULTS

A total of 114 patients who underwent axillary surgery for occult breast cancer were included. The 5-year disease-free survival was 74.5%, while overall survival was 88.5%. A total of 22.8% of patients underwent neoadjuvant treatment. Complete pathological response was achieved in 38.5%. Patients with complete nodal pathological response showed fewer events compared to patients with no complete pathological response after neoadjuvant treatment.

CONCLUSION

Although the sample size is limited, recent advances in breast cancer multimodal treatment indicate that targeted axillary surgery may be considered for the rare clinical presentation of occult breast cancer after neoadjuvant treatment.

TRIAL REGISTRY

Trial registration number UID 4184 24/07/2024 "retrospectively registered".

Proteomic profiling reveals biological processes and biomarkers involved in the pathogenesis of occult breast cancer

BACKGROUND

Occult breast cancer (OBC) is defined as axillary lymph node metastasis without any evidence of a primary tumor in the breast. Because of the limited number of clinical cases, the clinicopathological features and treatment recommendations of OBC are still controversial. In addition, its natural history is poorly understood and its proteomic signature remains unknown.

MATERIALS AND METHODS

We compared the clinicopathological features and prognosis of OBC patients and Non-OBC patients from the Surveillance, Epidemiology, and End Results (SEER) database and analyzed the effects of local treatment on the survival outcomes of OBC patients. Additionally, we performed a quantitative proteomic analysis for tissue samples of metastatic lymph nodes from OBC patients (OBC-LN), and paired tissue samples of metastatic lymph nodes (Non-OBC-LN) and primary tumors (Non-OBC-PT) from Non-OBC patients. We identified differentially expressed proteins in different comparable groups using Student's t test. Functional enrichment and protein-protein interaction network analyses were used to interpret the functions and interactions of the differentially expressed proteins in the comparison of OBC-LN vs Non-OBC-LN. Immunohistochemistry was used for the validation of the hub proteins.

RESULTS

Analysis of data from the SEER database demonstrated that OBC patients had a better prognosis than Non-OBC patients did and that either mastectomy or radiation therapy improved the outcomes of OBC patients. A total of 7208 comparable proteins were successfully quantified. Compared with those of the Non-OBC-LN samples, the OBC-LN protein profiles exhibited an active extracellular matrix and a thoroughly upregulated epithelial-mesenchymal transition phenotype. COL1A1, COL1A2, COL3A1, MMP2 and LUM were overexpressed in the OBC-LN samples and were identified as hub proteins. Immunohistochemical staining demonstrated that the five hub proteins were overexpressed in OBC-LN samples.

CONCLUSION

Our results provide insights for the clinical management of OBC and the proteomic signature of OBC offers molecular basis for further biological research.

Occult breast cancer in an older woman: A case report

Occult breast cancer (OBC) is a relatively rare clinical condition that can complicate differential diagnosis efforts and delay the administration of specific treatments. The individualized therapy of patients with OBC should be performed based on their clinical symptoms, imaging findings and pathological diagnosis. The present case study describes a 51-year-old woman with a painless left axillary tumor. The axillary lymph nodes of the patient were affected by invasive ductal carcinoma, as determined by histological analysis. However, the primary lesion was missed by numerous testing. The patient underwent surgery and testing for positron emission tomography/computed tomography (PET/CT). The present study comprehensively examined this case and offered a systematic analysis of the relevant scholarly works on the diagnosis, treatment and prognosis of OBC. Ultrasonography revealed the presence of three homogenous hypoechoic masses with irregular margins in the left axilla of the patient. PET/CT scanning identified multiple enlarged left axillary hypermetabolic lymph nodes. After that, the patient underwent a nipple-sparing mastectomy and an axillary lymphadenectomy. With the lymph nodes showing metastatic, infiltrating ductal carcinoma from the breast, ductal carcinoma in situ of the breast diagnosis was supported by a histological examination. Immunohistochemical staining revealed that resected lymph nodes were positive for both estrogen and progesterone receptors, consistent with the status of the breast as the primary tumor site. Following surgery, the patient underwent adjuvant chemotherapy treatment. At 12 months post-surgery, the patient remained well without evidence of disease. OBC cases lack the typical clinical and imaging findings associated with breast cancer, and a combination of axillary lymph node examination and immunohistochemistry is essential for accurately diagnosing affected patients. Ensuring the best patient outcomes necessitates accurate and prompt diagnosis, achieved by thorough physical examination, cautious utilization of diagnostic tools, personalized surgical interventions and histological investigation.

Trends in management and related outcomes for occult primary breast cancer

PURPOSE

Occult Primary Breast Cancer (OPBC) is a rare clinical condition in which breast cancer is located within the axillary lymph nodes, but no primary tumor is identified in the breast. We evaluated trends of neoadjuvant chemotherapy (NAC) use and subsequent axillary procedures in OPBC as well as outcomes for these patients.

METHODS

The National Cancer Database was used to identify adult women with cT0N1-3M0 breast cancer between 2012 to 2021 that underwent axillary lymph node surgery. Kaplan-Meier curves were used to evaluate survival between groups.

RESULTS

2759 patients met inclusion criteria. 86.2% underwent ALND alone in 2012, and this decreased to 65.6% in 2021. 4.7% underwent SLNB alone in 2012 and this increased to 16.2% in 2021 (p < 0.001). For patients who had undergone NAC, 46.4% of ALND patients had nodal pathologic complete response (nPCR), compared to 42.7% of SLNB + ALND and 66.4% of SLNB only patients. For patients with nPCR, there was no difference in overall survival (OS) between ALND, SLNB + ALND, and SLNB alone groups (p = 0.9912).

CONCLUSION

Most OPBC patients were treated with ALND, with a modest increase towards SLNB use during the study period. There was no difference in OS with respect to axillary surgical procedure in our population for those with nPCR after NAC. This suggests that for carefully selected OPBC patients with an excellent clinical response to NAC and negative SLNB, omission of ALND may be considered.

Locoregional Lymph Node Metastasis from Clinically Occult Breast Cancer: Prognostic Significance of Mastectomy

Materials and Methods

This study included patients registered in the national Danish Breast Cancer Group (DBCG) database between 2001 and 2015, with locoregional LNM as well as a bilateral negative mammography, ultrasonography, and physical examination of the breasts. Overall survival (OS) and invasive disease-free survival (IDFS) were compared by treatment groups, ALND + RT (axillary lymph node dissection and radiotherapy) or ALND + MAST ± RT (axillary lymph node dissection, mastectomy with or without radiotherapy).

Results

In total, 56 patients were included in the study, of which 37 were treated by ALND + RT, 16 by ALND + MAST ± RT, and the remaining three patients receiving different treatments. The median follow-up for the 53 OBC patients sorted by treatment group was 12.2 years (interquartile range: 10.1 years; 15.3 years). There was no significant difference in OS or IDFS between the treatment groups, except for a subgroup of 46 (out of 53) patients without verified in situ lesions before treatment, where ALND + RT treatment showed an improved OS (log-rank p=0.05).

Conclusion

Treating OBC patients with ALND and radiotherapy resulted in a similar outcome as treatment with ALND and mastectomy. This supports omission of mastectomy in favor of radiotherapy of the breast in these patients.

Clinicopathologic features and genomic profiling of female axillary lymph node metastases from adenocarcinoma or poorly differentiated carcinoma of unknown primary

PURPOSE

Axillary lymph node metastases from adenocarcinoma or poorly differentiated carcinoma of unknown primary (CUPAx) is a rare disease in women. This retrospective study intended to examine the clinicopathological features of CUPAx and compared CUPAx genetically with axillary lymph node metastases from breast cancer (BCAx), investigating differences in their biological behavior.

METHODS

We conducted the clinical and prognostic analysis of 58 CUPAx patients in West China Hospital spanning from 2009 to 2021. Gemonic profiling of 12 CUPAx patients and 16 BCAx patients was conducted by the FoundationOne CDx (F1CDx) platform. Moreover, we also compared the gene mutation spectrum and relevant pathways between the two groups and both TCGA and COSMIC databases.

RESULTS

The majority of the 58 CUPAx patients were HR-/HER2- subtype. Most patients received mastectomy combined radiotherapy (50 Gy/25f). CUPAx patients who received mastectomy instead of breast-conserving surgery had a more favorable overall prognosis. Radiotherapy in chest wall/breast and supraclavicular/infraclavicular fossa was the independent prognostic factor (HR = 0.05, 95%CI = 0.00-0.93, P = 0.04). In 28 sequencing samples (CUPAx, n = 12, BCAx, n = 16) and 401 TCGA-BRCA patients, IRS2 only mutated in CUPAx (33.33%) but amplified in BCAx (11.11%) and TCGA-BRCA (1.5%). Pathway analysis revealed that BCAx had more NOTCH pathway mutations than CUPAx. Enrichment analysis showed that CUPAx enriched more in mammary development and PML bodies than BCAx, but less in the positive regulation of kinase activity.

CONCLUSIONS

More active treatment methods, like chemotherapy, mastectomy and postoperative radiotherapy, could improve the prognosis of CUPAx. The differential mutation genes of CUPAx and BCAx might be associated with their respective biological behaviors like invasiveness and prognosis.

Clinicopathological features, psychological status, and prognosis of 33 patients with occult breast cancer

BACKGROUND

Occult breast cancer (OBC) has traditionally been considered to be a carcinoma of unknown primary origin with a favorable prognosis and can be treated as stage II-III breast cancer. Due to the small number of cases and limited clinical ex-perience, treatments vary greatly around the world and no standardized treat-ment has yet been established.

AIM

To investigate the clinicopathological features, psychological status and prog-nostic features of patients with OBC.

METHODS

The clinicopathological data of 33 OBC patients diagnosed and treated in the Affiliated Hospital of Xuzhou Medical University and Xuzhou Central Hospital from November 2015 to November 2022 were retrospectively analyzed. The psychological status of OBC patients was evaluated by the Self-rating Anxiety Scale and Self-rating Depression Scale. Patients' emotions, stress perception and psychological resilience were evaluated by the Positive and Negative Affect Schedule, the Chinese Perceived Stress Scale, and the Connor-Davidson Resilience Scale (CD-RISC), respectively. Patient survival was calculated using the Kaplan-Meier method, and survival curves were plotted for analysis with the log-rank test. Univariate and multivariate survival analyses were performed using the Cox regression model.

RESULTS

The 33 OBC patients included 32 females and 1 male. Of the 33 patients, 30 (91%) had axillary tumors, 3 (9%) had a neck mass as the primary symptom; 18 (54.5%) had estrogen receptor-positive tumors, 17 (51.5%) had progesterone receptor-positive tumors, and 18 (54.5%) had Her-2-positive tumors; 24 (72.7%) received surgical treatment, including 18 patients who underwent modified radical mastectomy, 1 patient who underwent breast-conserving surgery plus axillary lymph node dissection (ALND), and 5 patients who underwent ALND alone; 12 patients received preoperative neoadjuvant therapy. All 30 patients developed anxiety and depression, with low positive affect scores and high negative affect scores, accompanied by a high stress level and poor psychological resilience. There were no differences in the psychological status of patients according to age, body mass index, or menopausal status. The overall survival and disease-free survival (DFS) of all the patients were 83.3% and 55.7%, respectively. Univariate analysis demonstrated that the initial tumor site (P = 0.021) and node stage (P = 0.020) were factors that may affect patient prognosis. The 5-year DFS rate of OBC patients who received radiotherapy was greater (P < 0.001), while the use of different surgical methods (P = 0.687) had no statistically significant effect on patient outcomes. Multivariate analysis revealed that radiotherapy (P = 0.031) was an independent prognostic factor. Receiving radiotherapy had a significant effect on the CD-RISC score (P = 0.02).

CONCLUSION

OBC is a rare breast disease whose diagnosis and treatment are currently controversial. There was no significant difference in the efficacy of other less invasive surgical procedures compared to those of modified radical mastectomy. In addition, radiotherapy can significantly improve patient outcomes. We should pay attention to the psychological state of patients while they receive antitumor therapy.

Analysis of Prognoses according to Breast MRI Results in Patients with Axillary Lymph Node Metastases from an Unknown Primary Origin

PURPOSE

To compare the prognosis of patients with axillary adenocarcinoma from an unknown primary (ACUPax) origin with negative MRI results and those with MRI-detected primary breast cancers.

MATERIALS AND METHODS

The breast MRI images of 32 patients with ACUPax without signs of primary breast cancer on mammography and ultrasound (US) were analyzed. Spot compression-magnification mammography and second-look US were performed for the area of MRI abnormality in patients with positive results; any positive findings corresponding to the MRI abnormality were confirmed by biopsy. If suspicious MRI lesions could not be localized on mammography or US, MR-guided biopsy or excision biopsy after MR-guided localization was performed. We compared the prognosis of patients with negative breast MRI with that for patients with MRI-detected primary breast cancers.

RESULTS

Primary breast cancers were confirmed in 8 (25%) patients after breast MRI. Primary breast cancers were not detected on MRI in 24 (75%) patients, including five cases of false-positive MRI results. Twenty-three patients underwent axillary lymph node dissection (ALND) followed by whole breast radiation therapy (WBRT) and chemotherapy (n=17) or subsequent chemotherapy only (n=2). Recurrence or distant metastasis did not occur during follow up in 7/8 patients with MRI-detected primary breast cancers and 22/24 patients with negative MRI results. Regional recurrence or distant metastasis did not occur in any MR-negative patient who received adjuvant chemotherapy after ALND and WBRT.

CONCLUSION

The prognoses of MR-negative patients with ACUPax who received ALND and WBRT followed by chemotherapy were as good as those of patients with MRI-detected primary breast cancers.

De-escalation of surgery for occult breast cancer with axillary metastasis

Occult breast cancer presenting as axillary metastasis is rare and remains a diagnostic and therapeutic challenge. Evidence to guide clinical management is limited, and locoregional treatment remains nonstandardized and highly varied nationally. Historically, occult breast cancer was managed with modified radical mastectomy ± radiotherapy; however, equivalent local control and survival are observed with breast preservation and adjuvant whole breast radiotherapy. Axillary lymph node dissection remains the standard surgical approach to the axilla for occult breast cancer patients. De-escalating axillary surgery in a subset of occult breast cancer patients treated with neoadjuvant chemotherapy with good response to treatment may be appropriate, similar to the management of clinically node-positive patients in a known primary setting. As in other clinically node-positive breast cancer cases, thoughtful integration and tailoring of axillary surgery and regional nodal radiotherapy (for the varying extent of nodal burden) is an area of continued controversy and active investigation.

Best treatment options for occult breast cancer: A meta-analysis

Objectives

Occult breast cancer (OBC) is a rare malignant breast tumor. Because of the rare cases and limited clinical experience, a huge therapeutic difference has existed all over the world and standardized treatments have yet been established.

Methods

A meta-analysis was conducted using MEDLINE and Embase databases to identify the choice of OBC surgical procedures in all studies: (1) patients undergoing axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB) only; (2) patients undergoing ALND with radiotherapy (RT); (3) patients undergoing ALND with breast surgery (BS); (4) patients undergoing ALND with RT and BS; and (5) patients undergoing observation or RT only. The primary endpoints were mortality rates, the second endpoints were distant metastasis and locoregional recurrence.

Results

Among the 3,476 patients, 493 (14.2%) undergo ALND or SLNB only; 632 (18.2%) undergo ALND with RT; 1483 (42.7%) undergo ALND with BS; 467 (13.4%) undergo ALND RT and BS, and 401 (11.5%) undergo observation or RT only. After comparing the multiple groups, both groups 1 and 3 have higher mortality rates than group 4 (30.7% vs. 18.6%, p < 0.0001; 25.1% vs. 18.6%, p = 0.007), and group 1 has higher mortality rates than groups 2 and 3 (30.7% vs.14.7%, p < 0.00001; 30.7 vs. 19.4%, p < 0.0001). Group (1 + 3) had a prognosis advantage over group 5 (21.4% vs. 31.0%, p < 0.00001). There was no significant difference both in the distant recurrence rates and locoregional rates between group (1 + 3) and group (2 + 4) (21.0% vs. 9.7%, p = 0.06; 12.3% vs. 6.5%, p = 0.26).

Conclusion

On the basis of this meta-analysis, our study indicates that BS including modified radical mastectomy (MRM) and breast-conserving surgery (BCS) combined RT may appear as the optimal surgical approach in patients with OBC. RT cannot prolong both the time of distant metastasis and the local recurrences.

Reconceptualizing the clinicopathological features, locoregional therapy and prognostic factors of occult breast cancer in the era of molecular subtyping

To evaluate the clinical features, molecular subtypes, therapeutic strategies, and prognostic factors of occult breast cancer (OBC). Patients with T0-3/N1-3/M0 breast cancer diagnosed in 2010-2018 (n = 114,303, including 691 with OBC) were retrieved from the Surveillance, Epidemiology, and End-Results (SEER) database. The endpoints were overall survival (OS) and breast cancer-specific survival (BCSS). Compared with non-OBC, OBC presented significantly more adverse clinicopathological prognostic features. More patients with OBC underwent breast-conserving treatment (BCT) and less had axillary lymphadenectomy (ALD). Outcomes were more favorable in OBC cases compared with non-OBC cases (p = .002 for OS, p = .002 for BCSS). Triple-negative (TNBC) and HER2-enriched were the subtypes with the worst prognosis in OBC (p < .05). Prognosis was better for triple-negative OBC compared with the same subtype of non-OBC. N-stage was not a strong prognostic indicator of OBC (p > .05 for OS). Cases who underwent systemic chemotherapy alone without surgery had the worst prognosis among OBC patients. For locoregional therapy, mastectomy and radiotherapy could confer survival advantage; standard axillary lymph node dissection (ALND) and positive lymph node dissection (PLND) contributed notably to OS in OBC patients. Both OS and BCSS were better in OBC cases compared with non-OBC. Systemic chemotherapy alone without surgery is not appropriate for OBC treatment, and mastectomy plus standard axillary surgery is recommended. Patients with hormone receptor-positive and low burden of axillary lymph node metastasis may be spared from radiotherapy after undergoing standard axillary lymphadenectomy.

Axillary lymph node dissection plus radiotherapy may be an optimal strategy for patients with occult breast cancer

Background

Because of the rarity of occult breast cancer (OBC) and limited experience in OBC treatment, the optimal treatment strategy is unknown. This study aimed to compare the efficacy of axillary lymph node dissection (ALND) plus radiotherapy with that of mastectomy plus ALND in patients with OBC.

Methods

Relevant clinical data between January 2004 and December 2015 were retrospectively collected from the Surveillance, Epidemiology, and End Results database. The clinical characteristics and prognoses of patients who underwent ALND plus radiotherapy or mastectomy plus ALND were compared before and after propensity score matching.

Results

Overall, 569 eligible patients with OBC were included in this study. Of these, 247 patients underwent ALND plus radiotherapy and 322 underwent mastectomy plus ALND. The 5-year overall survival (OS) rates in the ALND plus radiotherapy group and the mastectomy plus ALND group were 89.2% and 80.6%, respectively; and the corresponding 5-year breast cancer-specific survival (BCSS) rates were 95.2% and 93.0%, respectively. After propensity score matching, the OS in the ALND plus radiotherapy group was significantly better than that in the mastectomy plus ALND group. In addition, further subgroup analyses revealed that ALND plus radiotherapy prolonged OS in the pN3 subgroup. Among patients receiving adjuvant chemotherapy, those who underwent ALND plus radiotherapy had better BCSS and OS than those who underwent mastectomy plus ALND.

Conclusions

ALND plus radiotherapy could improve the OS of patients with OBC, especially those with pN3 disease and those receiving chemotherapy. ALND combined with radiotherapy is the optimal treatment strategy for patients with imaging-negative OBC.

Case report: solitary splenic metastasis occurring 19 months after primary treatment for occult breast cancer

Occult breast cancer, commonly presenting with axillary lymphadenopathy, is an extremely rare entity of breast cancer. Metastasis to the spleen as a single site is rarely seen and has been little reported in literature. Herein we described a case of a 60-year-old patient who presented with an asymptomatic solitary splenic mass 19 months after axillary lymph node dissection, regional radiotherapy, and systemic therapy. Laparoscopic splenectomy was performed, and histopathological examination confirmed metastasis from occult breast cancer. Then, the patient was administered with oral vinorelbine and dual-targeted treatment. With over 10 months of follow-up, there is no evidence of recurrence or metastasis of malignancy. To our knowledge, this study reports the first case of solitary splenic metastasis from occult breast cancer and highlights the importance of considering splenic metastasis as the only site of recurrence during follow-up of primary cancer, regardless of its rarity. If possible, splenectomy may be a therapeutic strategy.

Clinicopathological characteristics and treatment outcomes of occult breast cancer: a population-based study

BACKGROUND

Occult breast cancer (OBC) is a special type of breast cancer. Because of its rarity, clinicopathological information is still insufficient, causing a controversial condition about its treatment recommendation. Thus, we aimed to clarify major clinicopathological information, treatment strategies and prognosis of OBC based on a large population.

METHODS

We retrospectively collected adult female OBC population from Surveillance, Epidemiology, and End Results database. We divided the whole cohort into two groups based on surgical treatment in-breast. Descriptive analysis of 18 clinicopathological variables was conducted. Survival analysis was performed based on different clinicopathological factors. Univariate and multivariate Cox regression analysis was performed to identify potential independent predictor for prognosis of OBC.

RESULTS

1189 OBC patients were in final analysis and most of them were diagnosed as an early-stage carcinoma. Patients received breast-conserving treatment (BCT) was nearly two times of ones received mastectomy. Patients receiving radiotherapy in BCT group were significantly more than patients receiving radiotherapy in mastectomy group (61.76 vs. 50.9%, P  <   0.001). After a median follow-up period of 62 months, 5-year and 10-year overall survival (OS) of all subjects was 81.6% and 68.8%, respectively. No significant difference in OS and breast-cancer specific survival (BCSS) was found between mastectomy and local breast-conserving surgery. Older age and larger number of positive lymph nodes causes a worse prognosis whereas radiotherapy brought a better clinical outcome for OBC patients.

CONCLUSIONS

OBC has a generally good prognosis. Less-intensive surgery does not negatively impact clinical outcomes of OBC while additional radiotherapy is totally beneficial to prolong OS and BCSS.

Surgical treatment trends and identification of primary breast tumors after surgery in occult breast cancer: a study based on the Japanese National Clinical Database-Breast Cancer Registry

BACKGROUND

Occult breast cancer (OBC) is classified as carcinoma of an unknown primary site, and the adequate therapy for OBC remains controversial. This retrospective study aimed to reveal the transition in breast cancer therapy and the frequency of primary breast tumors after resection in clinical OBC (cT0N+) patients using the Japanese Breast Cancer Registry database.

METHODS

We enrolled OBC patients with cT0N+ from the registry between 2010 and 2018. On the basis of the period of diagnosis, OBC patients were divided into the following two groups: 2010-2014 and 2015-2018. We described the transition in treatments and tumor characteristics. After breast resection, the frequency of pathological identification of primary tumors and tumor sizes was assessed.

RESULTS

Of the 687,468 patients registered, we identified 148 cT0N+ patients with a median age of 61 years. Of these patients, 64.2% (n = 95) received breast surgery (2010-2014: 79.1%, 2015-2018: 50.0%). Axillary lymph node dissection was performed in 92.6% (n = 137, 2010-2014: 91.6%, 2015-2018: 93.4%). The breast tumor size in the resected breast was 0-7.0 cm (median: 0 cm, 2010-2014: 0-7.0 cm [median: 0 cm], 2015-2018: 0-6.2 cm [median: 0 cm]). The pathological identification rate of the primary tumor was 41.1% (n = 39, 2010-2014: 40.4%, 2015-2018: 42.1%).

CONCLUSIONS

Breast surgery for cT0N+ decreased between 2010 and 2018. Despite the high identification rate of primary tumors, most tumors were small, and there was no significant change in the identification rate or invasive diameter of the identified tumors after 2010.

Prognosis of patients with axillary lymph node metastases from occult breast cancer: analysis of multicenter data

Purpose

This study was conducted to evaluate prognosis of patients with level I/II axillary lymph node metastases from occult breast cancer (OBC).

Materials and Methods

Data of 53 patients with OBC who received axillary lymph node dissection (ALND) positive/negative (+/–) breast-conserving surgery between 2001 and 2013 were retrospectively collected at seven hospitals in Korea. The median number of positive lymph nodes (+LNs) was 2. Seventeen patients (32.1%) had >3 +LNs. A total of 48 patients (90.6%) received radiotherapy. Extents of radiotherapy were as follows: whole-breast (WB; n = 11), regional lymph node (RLN; n = 2), and WB plus RLN (n = 35).

Results

The median follow-up time was 85 months. Recurrence was found in four patients: two in the breast, one in RLN, and one in the breast and RLN. The 5-year and 7-year disease-free survival (DFS) rates were 96.1% and 93.5%, respectively. Molecular subtype and receipt of breast radiotherapy were significantly associated with DFS. Patients with estrogen receptor negative, progesterone receptor negative, and human epidermal growth factor receptor 2 negative (ER-/PR-/HER2-) subtype had significantly lower 7-year DFS than those with non-ER-/PR-/HER2- tumor (76.9% vs. 100.0%; p = 0.03). Whole breast irradiation (WBI) was significantly associated with a higher 7-year DFS rate (94.7% for WBI group vs. 83.3% for non-WBI group; p = 0.01). Other factors including patient’s age, number of +LNs, taxane chemotherapy, and RLN irradiation were not associated with DFS.

Conclusion

Patients with OBC achieved favorable outcome after ALND and breast-targeting treatment. Molecular subtype and receipt of WBI was significant factors for DFS.

Occult breast cancer: Where are we at?

Occult breast cancer (OBC) is described as an axillary metastatic carcinoma without detection of a primary breast lesion and is uncommon. Significant advances in breast imaging have occurred since its description, decreasing its incidence. However current management is based upon old studies, with variable clinical, radiological and pathological definitions of OBC. We suggest standardised definitions of OBC to facilitate more homogenous data representation in the literature. This review also discusses the conflicting heterogeneous data and its influence in determining the current management guidelines. We discuss whether the current significant surgical recommendations are necessary and postulate whether they could be safely substituted with less invasive management.

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Pathological occult breast cancer is defined as no lesion detectable on MRI or pathological breast lesion post-surgery when examined at 5mm slices

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NAC in OBC may result in the de-escalation of axillary surgery.

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Current evidence indicates that ALND with ipsilateral breast RT has equivalent outcomes compared to ALND with mastectomy

The Effect of Hospital Volume on Outcomes of Patients with Occult Breast Cancer

INTRODUCTION

With limited data in regards to management, occult breast cancer (OBC) poses a challenging surgical scenario. Current surgical management includes axillary lymphadenectomy (ALND) with or without mastectomy. We sought to investigate the impact of hospital volume on surgical approach and survival outcomes of patients with OBC.

METHODS

Patients with cT0N+ breast cancer were selected from the National Cancer Data Base (NCDB, 2004-2014). Primary outcome was overall survival (OS), calculated using Kaplan-Meier methods compared according to hospital volume: community cancer center (CC), comprehensive community cancer center (COMP), and academic center (AC). Secondary outcome was the rate of modified radical mastectomy (MRM).

RESULTS

We identified 574 patients with OBC, 11.1% were treated at a CC, 51.8% at a COMP, and 37.0% at an AC. Patients treated at CC had lower socioeconomic status compared with COMP or AC (23.1%, 14.1%, 19.3%; p = 0.005, respectively). There was no difference in access to radiation therapy (p = 0.888) or neoadjuvant chemotherapy (p = 0.221). Patients treated at CC had worse OS compared with COMP or AC (87.04, 105.29, 108.06 mo, p = 0.026, respectively). There was an increased rate of MRM at CC compared with COMP or AC (54.7%, 41.2%, 30.5%, p = 0.003, respectively).

CONCLUSIONS

A direct association seems to exist between hospital volume and outcomes of patients with OBC. Patients with OBC treated at AC were more likely to undergo breast-conserving approaches and had better survival than those treated at CC.

Axillary Downstaging in Occult Primary Breast Cancer After Neoadjuvant Chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NAC) is increasingly used for clinically node-positive (cN+) tumors with intact primary breast cancer (IPBC) to downstage the axilla, and those who convert to cN0 may be eligible for sentinel lymph node biopsy (SLNB). Rates of axillary downstaging in occult primary breast cancer (OPBC) are unknown.

OBJECTIVE

The aim of this study was to determine the frequency of nodal pathologic complete response (pCR) following NAC in a cohort of patients with OPBC.

METHODS

Twenty-eight patients with stage II/III OPBC treated between January 2008 and December 2019 were identified. Twenty patients had cN1-3 OPBC, pretreatment lymph node needle biopsy, and received NAC; these constituted the study population. Treatment factors and nodal pCR rates were summarized by tumor subtype.

RESULTS

Median age at diagnosis was 54 years. Most patients presented with cN1 disease (75%) and ductal histology (80%). Nodal pCR was seen in 16/20 (80%) patients. Eight (40%) patients were triple negative, 6 (30%) were estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER +/HER2 -), and 6 (30%) were HER2 positive, with pCR rates of 88%, 50%, and 100%, respectively. Among the 15 patients who presented as cN1, 14 (93%) converted to cN0 following NAC. Of these, nine underwent SLNB and all achieved nodal pCR (100%).

CONCLUSION

In this small series, 80% of OPBC patients achieved nodal pCR following NAC. pCR rates varied by receptor profile, being lowest in the ER positive/HER2 negative group and highest in the HER2 positive group (50-100%); however, these rates are excellent and numerically exceed those in the literature for IPBC. Given the pCR rate, SLNB may be an option in select OPBC patients who downstage following NAC.

Surgical Management of the Axilla in Patients with Occult Breast Cancer (cT0 N+) After Neoadjuvant Chemotherapy

BACKGROUND

Occult breast cancer (OBC) is a rare clinical entity. Current surgical management includes axillary lymphadenectomy (ALND) with or without mastectomy. We sought to investigate the role of sentinel lymph node biopsy (SLNB) in patients with OBC treated with neoadjuvant chemotherapy (NAC).

METHODS

Patients with clinical T0N+ breast cancer were selected from the National Cancer Data Base (NCDB, 2004-2014) and compared according to axillary surgical approach, SLNB (≤ 4 LNs) or ALND (> 4 LNs). Primary outcome was overall survival (OS), calculated using Kaplan-Meier methods. Secondary outcome was complete pathological response (pCR).

RESULTS

A total of 684 patients with OBC were identified: 470 (68.7%) underwent surgery upfront and 214 (31.3%) received NAC. Of the NAC patients, 34 (15.9%) underwent SLNB and 180 (84.1%) ALND. One hundred and fifty-three (72%) patients received radiotherapy (RT). There was no difference in pCR rates between the ALND and SLNB (34.3% vs 24.5%, respectively p = 0.245). In patients undergoing surgery first, improved OS was observed with ALND compared to SLNB (106.9 vs 85.5 months, p = 0.013); however, no difference in OS was found in patients who received NAC (105.6 vs 111.3 months, p = 0.640). RT improved OS in patients who underwent NAC followed by SLNB (RT, 123 months vs no RT, 64 months, p = 0.034). Of NAC patients who did not undergo RT, ALND had superior survival compared to SLNB (113 vs 64 months, p = 0.013).

CONCLUSION

This is the first comparative analysis assessing the surgical management of the axilla in patients with OBC who underwent NAC. In this population, there was a decrease in survival in patients who underwent SLNB alone; however, with the addition of RT, there was no difference in OS between SLNB and ALND. SLNB plus RT may be considered as an alternative to ALND in patients with OBC who have a good response to NAC.

Outcome of breast-conserving treatment for axillary lymph node metastasis from occult breast cancer with negative breast MRI

Purpose

We conducted this study to investigate the prognosis and failure pattern after breast-conserving treatment (BCT) in patients with occult breast cancer (OBC) with negative breast magnetic resonance imaging (MRI) (MRI-OBC).

Materials and methods

Survival rates and failure patterns in 66 patients who received axillary lymph node dissection (ALND) and BCT for MRI-OBC between 2001 and 2013 at seven hospitals were analyzed. OBC was defined as adenocarcinoma in the axillary lymph node (ALN) +/− supraclavicular (SCN) or internal mammary lymph node (IMN) with a negative breast MRI.

Results

Fifty-four patients had only ALN metastasis (ALN only), and 12 patients had ALN metastasis along with SCN or IMN metastasis (ALN + SCN/IMN). Median follow-up was 82 months. The 5-year overall, disease-free, and breast cancer-free survival rates were 93.4%, 92.1%, and 96.8%, respectively. Nine patients experienced recurrence: breast (n = 4), regional lymph nodes (RLN, n = 1), distant metastases (DM, n = 2), breast/RLN (n = 1), and breast/RLN/DM (n = 1). Five-year disease-free survival was significantly higher in ALN only patients compared to ALN + SCN/IMN patients (96.1% vs. 75.0%; p = 0.02).

Conclusions

Patients with MRI-OBC were successfully treated with BCT. There was a small risk of ipsilateral breast cancer recurrence. Failure patterns depended on the extent of initial disease.

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Occult breast cancer (OBC) presenting with axillary metastases is a rare disease.

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This study reports on the outcome of OBC with negative breast MRI (MRI-OBC).

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Patients with MRI-OBC were successfully treated with breast-conserving treatment.

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Very few breast recurrences occurred when whole breast radiotherapy was used.

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Failure patterns of MRI-OBC depended on the initial extent of nodal involvement.

The effect of local therapy on breast cancer-specific mortality of women with occult breast cancer and advanced nodal disease (N2/N3): a population analysis

PURPOSE

Current NCCN guidelines for occult breast cancer (OBC) recommend modified radical mastectomy, with the option for breast preservation with radiation instead of mastectomy for N1 patients. Our aim was to compare the effect of local therapy-mastectomy versus breast radiation-on breast cancer-specific mortality (BCSM) in a contemporary cohort of OBC patients of all nodal stages.

METHODS

Competing risk analyses were performed to evaluate the effect of local therapy, nodal stage, and other demographic and clinical prognostic variables on risk of BCSM for women registered in the SEER database with T0N+M0 breast cancer from 2004 to 2015.

RESULTS

Of the 353 women with OBC who underwent axillary nodal dissection, 152 received breast radiation and 201 underwent mastectomy. Overall, 57.5% had N1 disease, 54.4% had estrogen receptor (ER) positive tumors, 80.7% were white, and 88.1% received chemotherapy. Women treated with radiation were older (p < 0.001). The two groups were comparable with respect to all other variables analyzed. During a median follow-up of 66 months, 32 women died from breast cancer (radiation: 11, mastectomy: 21). Five-year cumulative incidence of BCSM was 8.0% ± 2.6% with radiation versus 10.9% ± 2.6% with mastectomy (p = 0.309). On multivariate analysis, independent predictors of BCSM included older age, higher N stage, and ER negativity, but the type of local therapy was not significantly associated with outcome.

CONCLUSIONS

These results suggest that breast preservation is a reasonable alternative to mastectomy for OBC patients, regardless of nodal stage.

Clinicopathological characteristics and treatment outcomes of occult breast cancer: a SEER population-based study

Background

Occult breast cancer (OBC) is a rare type of breast cancer that has not been well studied. The clinicopathological characteristics and treatment recommendations for OBC are based on a limited number of retrospective studies and thus remain controversial.

Patients and methods

We identified 479 OBC patients and 115,739 non-OBC patients from 2004 to 2014 in and the Surveillance, Epidemiology, and End Results (SEER) database. The clinicopathological characteristics and survival outcomes were compared between OBC and non-OBC patients. We used the propensity score 1:1 matching analysis to evaluate OBC vs non-OBC comparison using balanced groups with respect to the observed covariates. We further divided the OBC population into four groups based on different treatment strategies. Univariable and multivariable analyses were used to calculate and compare the four treatment outcomes within the OBC population.

Results

OBC patients were older, exhibited a more advanced stage, a higher rate of negative estrogen receptor and progesterone receptor status, a higher rate of HER2-positive status, and a higher rate of ≥10 positive lymph nodes, and were less likely to undergo surgical treatment than non-OBC patients. After adjustments for clinicopathological factors, the OBC patients exhibited a significantly better survival than the non-OBC patients (P<0.001). This result was confirmed in a 1:1 matched case–control analysis. Within the four OBC treatment groups, we observed no difference in survival among the mastectomy group, the breast-conserving surgery (BCS) group, and the axillary lymph node dissection (ALND)-only group. The multivariable analysis revealed that the sentinel lymph node dissection-only group had the worst prognosis (P<0.001). Conclusion: OBC has unique clinicopathological characteristics and a favorable prognosis compared with non-OBC. BCS plus ALND and radiotherapy showed a survival benefit that was similar to that of mastectomy for OBC patients.

A retrospective study of optimal surgical management for occult breast carcinoma: Mastectomy or quadrantectomy?

The diagnosis and treatment for occult breast carcinoma (OBC) remain controversial because of no detectable primary lesions. We aimed to analyze optimal surgical management for OBC.A total of 26 female patients diagnosed with OBC, which were based on available criteria, were collected at a single clinic center from January 2005 to May 2016. We classified all patients into 4 groups: group A1, mastectomy with axillary lymph node dissection (ALND) + radiotherapy (RT); group A2, mastectomy with ALND; group B1, quadrantectomy with ALND + RT; group B2, quadrantectomy with ALND. Patient characteristics, disease-free survival, and overall survival were compared between groups.There were 14 cases in group A1, 5 cases in group A2, 4 cases in group B1, and 3 cases in group B2. Baseline characteristics were similar among groups. Compared with OBC patients treated with quadrantectomy, the disease-free survival (DFS) and overall survival (OS) rate of those treated with mastectomy had significantly improved (A1 vs. B1, DFS: hazard ratio [HR] 0.018, 95% confidence interval [CI] 0.001-0.241, P = .002; OS: HR 0.002, 95% CI 0.000-0.102, P = .002). Patients treated with radiotherapy had higher local recurrence and OS rate compared with patients treated with no radiotherapy on univariate survival analysis (A1 vs. A2, DFS: HR 0.018, 95% CI 0.001-0.240, P = .002; OS: HR 0.005, 95% CI 0.000-0.170, P = .003).The diagnosis of OBC will need continuous improvement with advances of diagnostic breast imaging. Modified radical mastectomy + RT is still a safe and effective choice.

Comparable Survival between Additional Radiotherapy and Local Surgery in Occult Breast Cancer after Axillary Lymph Node Dissection: A Population-based Analysis

Purpose: To investigate the clinical value of additional local treatment strategies in occult breast cancer (OBC) after axillary lymph node dissection (ALND). Methods: Patients diagnosed with OBC between 1990 and 2013 were included from the Surveillance, Epidemiology, and End Results registry database. The significant risk factors of cause-specific survival (CSS) and overall survival (OS) were identified using univariate and multivariate Cox regression analyses. Results: We identified 980 patients, including 219 (22.3%), 252 (25.7%), 263 (26.8%), and 246 (25.1%) of patients underwent ALND, ALND + radiotherapy (RT), ALND + surgery (S) (mastectomy or breast-conserving surgery), and ALND + S + RT, respectively. Patients with younger age, diagnosed before 2000, advanced nodal stage, ER-negative disease, and PR-negative disease were more likely to undergo additional local treatment compared with ALND only. The 10-year rate CSS of the ALND only group was 57.2%, while that of the ALND + RT, ALND + S, and ALND + S + RT groups was 78.0%, 81.0%, and 71.5%, respectively (p < 0.001). The 10-year OS rate in the ALND only, ALND + RT, ALND + S, and ALND + S + RT groups was 46.0%, 69.5%, 66.1%, and 67.0%, respectively (p < 0.001). Multivariate analysis indicated that older age, advanced nodal stage, and ALND only were independent risk factors for decreased CSS and OS. CSS and OS among the groups including ALND + RT, ALND + S, and ALND + S + RT were not significantly different. Conclusions: Additional local treatment (local surgery or RT) improves survival outcomes compared with ALND only in OBC after ALND. ALND + RT may be the optimal local treatment for OBC due to no different in survival outcomes and cosmesis is better.

Current Management of the Axilla

Despite advances in estimating prognosis and predicting response to adjuvant systemic therapy, the status of the axillary lymph nodes remains a critical component in initial surgical planning and in determining therapeutic strategies for patients with breast cancer. Buoyed by evidence from multi-institutional randomized clinical trials, the last 2 decades have witnessed remarkable and practice-changing advances in our approach to the axilla. This review concentrates on the current best practice in axillary management for both node-negative and node-positive patients, with particular focus on the evolving management of the axilla in the era of neoadjuvant systemic therapy.

Clinical and pathological portraits of axillary presentation breast cancer and effects of preoperative systemic therapy

There is a lack of investigation into the biological characteristics and preoperative systemic therapy (PST) for occult breast cancer (OBC). For this study, departmental records in Breast Disease Center of Peking University First Hospital from January 2008 to December 2015 were retrospectively reviewed to identify cases of OBC. Eleven cases were included, and all patients were female, with a median age of 56 (range: 29-75) years. The sensitivity of magnetic resonance imaging (MRI) was 100%, and the false positive rate was 33.3%. Based on histologic analysis of the axillary node, 9 (81.8%) cases were grade 3, and 2 (18.2%) cases were grade 2; 4 (36.4%) cases were ≥10% estrogen receptor (ER) positive and 6 (54.5%) human epidermal growth receptor 2 (HER2) positive. Nine cases (81.8%) exhibited over 30% Ki67 expression. PST was performed in 5 of the 11 cases. The lymph node response rate was 100% (5/5), but no complete remission was achieved. In conclusion, aggressive subtypes were predominant among the included cases, and PST should be considered for OBC treatment options.

Oncologic Outcomes After Treatment for MRI Occult Breast Cancer (pT0N+)

BACKGROUND

Studies assessing outcomes in occult breast cancer have often included women treated before the routine use of magnetic resonance imaging (MRI). This study examined outcomes for patients presenting with axillary adenopathy and no primary breast tumor detectable by MRI or other imaging methods.

METHODS

All patients with axillary nodal metastases consistent with breast carcinoma and no breast primary tumor detectable by physical exam, mammography, or MRI treated between 1 January 1996 and 30 June 2011 were identified from an institutional database. Data were collected on local, regional, and distant recurrences.

RESULTS

For the study, 38 patients were identified. Modified radical mastectomy (MRM) was performed for 13 of the patients, whereas 25 of the patients underwent axillary dissection (ALND) and whole-breast radiotherapy (WBRT). Most of the women had pathologic N1 disease [median number of positive nodes, 2 (MRM cohort) and 3 (ALND + WBRT cohort); p = 0.38]. All the patients received chemotherapy, and 30 (79%) of the 38 patients received an anthracycline and taxane. Regional nodal radiation was used for 60% of those with ALND + WBRT and for all 46% of the MRM patients who received chest wall radiotherapy. During a median follow-up period of 7 years, there were no nodal recurrences. Two patients treated with ALND + WBRT had in-breast recurrences, whereas none in the MRM group experienced a local recurrence. The proportion that experienced distant disease was similar between the MRM cohort (1 of 13) and the ALND + WBRT cohort (2 of 25).

CONCLUSION

Breast cancer presenting as axillary adenopathy with no detectable primary tumor is rare. Breast conservation with WBRT is a viable option for patients with a diagnosis of occult breast cancer and a negative preoperative MRI.

Evaluation of the Benefit of Radiotherapy in Patients with Occult Breast Cancer: A Population-Based Analysis of the SEER Database

Purpose

Few studies for occult breast cancer (OBC) have evaluated the effect of radiotherapy (RT) after mastectomy or axillary lymph node dissection (ALND) with/without breast surgery. Therefore, we investigated clinicopathologic factors of OBC with the impact of postoperative RT to determine its prognostic significance using large population-based data.

Materials and Methods

We performed a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) database from 1983 to 2013. A total of 1,045 eligible patients with OBC were identified. We compared overall survival (OS) using Cox proportional hazards regression with propensity score matching after verifying an imbalance of prognosticators between RT group (n=518) and non-RT group (n=479).

Results

Patients with age < 70 (p=0.033), married marital status (p < 0.001), undergoing ALND (p < 0.001), more examined lymph nodes (LNs) (p < 0.001), and more metastatic LNs (p < 0.001) were more likely to receive RT. Multivariate analysis after propensity score matching (n=798) showed that patients treated with RT survived significantly longer than those without RT (5-year OS, 81.5% vs. 78.3%; p=0.014). A significantly prolonged OS was observed when RT was given to patients treated with mastectomy (p=0.033), those treated with ALND (p=0.036), or those with more than seven metastatic LNs (p=0.016).

Conclusion

RT may offer survival benefit in OBC even after mastectomy or ALND, especially in patients with more than seven metastatic LNs. Further prospective studies are needed to validate these findings.

Angiosarcoma arising in the non-operated, sclerosing breast after primary irradiation, surviving 6 years post-resection: A case report and review of the Japanese literature

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This is the first report of angiosarcoma occurring after radiation on a non-operated breast.

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The patient underwent mastectomy, surviving disease free for 6 years, despite the generally poor prognosis of angiosarcoma.

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The potential difficulties of diagnosing angiosarcoma against background fibrosis caused by radiation should be kept in mind.

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Kaplan-Meier analysis of 60 Japanese breast angiosarcoma patients showed significantly better prognosis in patients with a tumor 2 cm or smaller.

Introduction

Angiosarcoma consists only 0.04% of all breast malignancies and has a poor prognosis. This is the first reported case of an angiosarcoma arising in the non-operated breast after primary irradiation for occult breast cancer. The patient underwent mastectomy, surviving disease free for 6 years.

Presentation of case

A 73-year-old woman with a past history of irradiation of the non-operated left breast complained of skin thickening and crust formation on the left nipple 8 years post-irradiation. Considering the clinical history and radiological studies, recurrent cancer was suspected and biopsy was performed. However, no proof of malignancy was obtained. As clinical symptoms continued to advance, informed consent was obtained and mastectomy was performed. Histological examination of the surgical specimen revealed angiosarcoma.

Discussion

In this case, angiosarcoma occurred after radiation on a non-operated breast. Preoperative diagnosis was not achieved even with two cytology specimen and one biopsy. Each showed only fibrosis and inflammatory changes. The background breast tissue inflammation should have been caused by radiation. Marked fibrosis and the rather small number of sarcoma cells in the breast tumor in this case may be why bioptic diagnosis was difficult. Kaplan-Meier analysis of 60 Japanese breast angiosarcoma patients showed significantly better prognosis in patients with a tumor 2 cm or smaller.

Conclusion

Angiosarcoma may occur in the non-operated breast, post irradiation. The potential difficulties of diagnosing angiosarcoma against background fibrosis should be kept in mind. Initial radical surgery currently represents the only effective treatment for improving survival in these patients.