Stereotactic Core-Needle Breast Biopsy by Surgeons

Abstract

Objective

To evaluate the reliability of stereotactic core-needle breast biopsy (SCNB) performed by surgeons to detect histologically benign tissue.

Summary Background Data

Stereotactic core-needle breast biopsy is widely used to obtain tissue for definitive pathologic diagnosis of mammographically suspicious breast lesions. It has an incidence of malignancy detection similar to that of open biopsy. The potential for sampling error is a concern. Minimal data regarding follow-up and failure rate are available, especially from series performed exclusively by surgeons.

Methods

Pertinent medical records of all patients who underwent SCNB between April 1995 and October 1997 were reviewed. Breast lesions were classified by mammographic Breast Imaging—Reporting and Data Systems (BI-RADS) categories before SCNB. Benign biopsy specimens were classified as nonproliferative or proliferative. Malignant lesions and those with atypical histopathology by SCNB were excluded from this analysis. All lesions initially reported as benign were followed up mammographically for at least 2 years for any suspicious change requiring repeat biopsy.

Results

During the 31-month period, SCNB was performed on 694 lesions in 619 patients. Histologic evidence of malignancy was found in 112 lesions (16%). The initial histologic diagnosis for the remaining 582 lesions was benign. Four hundred lesions were available for follow-up; of these, 373 (93%) were mammographically categorized as BI-RADS 3 (probably benign) or 4 (suspicious). Three hundred forty-three lesions were categorized as nonproliferative and 151 as proliferative (94 had combined nonproliferative and proliferative histology). Follow-up ranged from 24 to 48 months (mean 33 months). During the follow-up period, 87 lesions (21.8%) underwent either image-guided or open biopsy. At the time of follow-up rebiopsy, ductal carcinoma in situ was found in four lesions and infiltrating ductal carcinoma was found in one, for an overall false-negative rate of 4.3% (5/117) and a negative predictive value of 98.8% (395/400). For the five false-negative cases, the interval from initial SCNB to definitive diagnosis ranged from 7 to 36 months. No correlation was found between the type of initial histopathology and development of malignancy.

Conclusions

These results support SCNB as an alternative to open biopsy and show the reliability of SCNB when benign pathology is obtained. However, given the possibility of sampling error and the nature of breast disease, close mammographic and clinical follow-up is necessary. The false-negative rate and negative predictive value in this series compare favorably with those in other reports, supporting the fact that surgeons can confidently use SCNB in the evaluation and treatment of breast disease.

Heightened awareness of breast cancer and advances in imaging techniques have led to a tremendous increase in the number of breast biopsies performed annually in the United States. ^1,2 Coupled with reports of 20% to 30% improvement in breast cancer death rates in patients who undergo routine screening mammography, ^3,4 the increased use of breast\. biopsy has led to earlier detection and better clinical outcomes. Numerous reports ^5–10 have shown that stereotactic core-needle breast biopsy (SCNB) is a safe, cost-effective, and accurate alternative to open biopsy, and surgeons can successfully use it in their practices. ^1,11–13 This method of tissue sampling may become the standard of care in the management of mammographically detected breast abnormalities.

A malignant diagnosis at SCNB allows definitive surgical treatment planning, ¹⁴ but a benign diagnosis at biopsy is typically followed with interval mammography at 6 to 12 months after the biopsy. As with needle-localized excisional biopsy (NLB), sampling error is a risk with SCNB, and false-negative benign results are particularly worrisome, because this may delay the diagnosis. Determination of the false-negative rate has been hampered by the lack of long-term follow-up data after SCNB. Recent reports from series in which SCNB was performed predominantly by radiologists indicate false-negative rates of 0% to 4%. ^15–19 This report reviews follow-up data (≥2 years) and rebiopsy results in patients with initially benign SCNB in a series of patients where SCNB was performed by surgeons.

METHODS

Records of patients with breast lesions sampled by SCNB at our institution during the initial 31 months that the service was available, from April 1995 to October 1997, were retrospectively reviewed. Lesions that were malignant or demonstrated atypical hyperplasia at the initial biopsy were excluded from this study. Data from patients with an initially benign diagnosis were collected. By retrospective review, screening mammograms that led to the initial biopsy were classified according to the degree of suspicion for malignancy in a manner consistent with the Breast Imaging—Reporting and Data Systems (BI-RADS) classification of the American College of Radiology. ²⁰ The number of core tissue biopsy samples taken at each procedure was noted. All stereotactic biopsies were performed by surgeons using the Mammotest table and Mammovision computer station (Fischer Imaging, Denver, CO) and a spring-loaded 14-gauge needle with a 19-mm sampling notch (Manan Medical Products, Northbrook, IL).

Pathology reports were reviewed to designate a nonproliferative or a proliferative benign diagnosis. Lesions classified as nonproliferative included fibrocystic change, fibrous mastopathy, apocrine metaplasia, fat necrosis, lymph node, and fibrous/scar tissue. Proliferative histologic results included fibroadenoma, sclerosing adenosis, ductal epithelial hyperplasia, and adenosis.

Follow-up information was obtained from mammogram reports, office records, and primary care physicians. Mammograms were reviewed for any suspicious change in the original lesion that might require repeat biopsy. The standard mammogram follow-up recommendation after benign SCNB was 6-month unilateral mammography, followed by a bilateral mammographic examination at 12 and 24 months. Stability at this point usually resulted in the return of the patient to routine clinical evaluation and appropriate mammographic screening. The follow-up was divided into 6-month intervals to determine when a mammographic change occurred and whether rebiopsy was performed. Rebiopsy was performed using either image-guided techniques or open surgical biopsy. Pathology reports from rebiopsied lesions were reviewed and checked for concordance with initial benign results and for the presence of malignant histology. Reports that showed evidence of malignancy at the repeat biopsy were reviewed to determine whether sampling error was responsible or whether new malignant tissue had developed in the previously biopsied site. The number of malignancies diagnosed at the repeat biopsy divided by the total number of malignancies found in the 694 lesions yielded the false-negative rate. Sensitivity, specificity, positive predictive value, and negative predictive value were also calculated.

RESULTS

During the study period, 619 patients underwent SCNB of 694 lesions. Malignancy was found in 112 lesions (16%), and these were not subjected to further review. Eleven lesions showed atypical ductal hyperplasia, underwent NLB, and were excluded. Of the 571 lesions initially determined to be benign, 171 (30%) did not have adequate follow-up to be included, leaving 400 (70%) lesions for evaluation. Reasons for inadequate follow-up included patient noncompliance (n = 65), unrelated patient death (n = 7), patients with pending mammographic follow-up (n = 5), and patients unable to be located (n = 94). The screening mammograms, repeat biopsy results, and follow-up mammographic and clinical findings for each of the remaining 400 benign lesions were reviewed.

Follow-up of the 400 evaluable benign lesions ranged from 24 to 48 months (average 33 months). One hundred eighty-four lesions (46%) had at least 36 months of benign follow-up; of these, 55 lesions (14%) showed no evidence of malignancy at 48 months of follow-up.

The BI-RADS classification for these 400 lesions at the time of initial SCNB was as follows: 217 (54.3%) BI-RADS 4 (suspicious), 156 lesions (39.0%) BI-RADS 3 (probably benign), 26 lesions (6.5%) BI-RADS 2 (benign), and 1 lesion (0.3%) BI-RADS 5 (malignant). The BI-RADS 5 lesion proved to be fat necrosis by SCNB and NLB.

Table 1 shows the distribution of cases based on the number of core samples obtained. At the initial SCNB, more than six cores were obtained in 318 lesions (79.5%) and five or fewer cores were obtained in 82 lesions (20.5%). All five false-negative lesions had at least six cores taken during the initial biopsy.

Table 1. CORE SAMPLES

Table 2 reflects the distribution of benign histopathology recorded at SCNB. Three hundred forty-three lesions showed nonproliferative pathology and 151 lesions were found to have proliferative pathology (94 had combined findings). Fibrocystic changes constituted the majority (52%) of the nonproliferative lesions, whereas ductal epithelial hyperplasia was the most common proliferative finding (48%).

Table 2. INITIAL HISTOPATHOLOGY

* 94 lesions had both nonproliferative and proliferative findings.

Ninety-four repeat biopsies were performed on 87 lesions during the follow-up period for an overall rebiopsy rate of 21.8%. NLB was performed on 30 lesions in the first 3 months after SCNB, and all were benign. Thirty-five other NLBs were performed at a later point during the follow-up period. Twenty-nine lesions were sampled by repeat SCNB (n = 20), ultrasound-guided biopsy (n = 6), or ultrasound-guided needle aspiration (n = 3). Five of these lesions showed evidence of malignancy at rebiopsy, as tabulated in Table 3. The indication for rebiopsy in each of these five was the follow-up mammogram result. Three were diagnosed by NLB and two by repeat SCNB. Ductal carcinoma in situ (DCIS) was present in four and invasive carcinoma in one. Because three of the four DCIS lesions were discovered by NLB, it was difficult to determine whether the areas of DCIS described in the pathology reports were indeed the same areas originally targeted by SCNB. The other DCIS lesion and the lesion found to have invasive carcinoma were diagnosed by repeat SCNB. If we consider these as “true misses” by SCNB, this results in five patients who had delays in diagnosis and a false-negative rate of 4.3%. The interval between initial SCNB pathology and final pathology was less than 21 months for four patients and 36 months for the fifth patient. None of these patients showed evidence of metastatic or recurrent disease. Sensitivity, specificity, false-negative rate, false-positive rate, positive predictive value, and negative predictive value are summarized in Table 4.

Table 3. SUMMARY OF FIVE FALSE-NEGATIVE RESULTS

AD/MC; asymmetric density/microcalcifications; DCIS, ductal carcinoma in situ; NLB, needle-localized excisional biopsy; SCNB, stereotactic core-needle biopsy.

Table 4. FOLLOW-UP RESULTS

* It was assumed that the rate of false-negatives on those lost to follow-up would be the same as that for those patients observed on follow-up. Thus it was assumed that 4.3% or 2 of the 171 lost to follow-up would have been malignant.

Sensitivity = 95.7% (*94.1%) Specificity = 100%

False-negative rate = 4.3% (*5.9%) False-positive rate = 0%

Positive predictive value = 100% Negative predictive value = 98.8%.

If the 171 lesions lost to follow-up were considered, the statistical assumption can be made that two false-negatives would be found in this group. This would raise the false-negative rate to 5.9% and lower the sensitivity to 94.1%. A 95% confidence interval (based on the binomial distribution) for the true false-negative rate is 2.5% to 12.5%, assuming that 119 malignancies would be found in the series of 571 lesions.

DISCUSSION

Since the use of mammography in the early diagnosis of breast disease began, NLB has been the mainstay in management of nonpalpable breast lesions. Although this procedure has been effective, a recent summary of 17 studies concluded that NLB has an average miss rate (percentage of cases in which biopsy failed to remove the index lesion) of approximately 2.8%. ²¹ Reported reasons for failure to excise the lesion included inaccurate needle placement, needle dislodgement before excision, failure to obtain a specimen radiograph, and actual location of microcalcifications in the skin. ^2,21 Despite these limitations, NLB is the gold standard to which other procedures are compared.

Stereotactic core-needle biopsy is receiving close scrutiny as a minimally invasive, cost-effective, and accurate method for evaluating mammographically detected lesions. In a multiinstitutional study by Parker et al, ⁶ data from 6,000 lesions sampled by SCNB demonstrated that this procedure is a reproducible and reliable alternative to open surgical biopsy. Numerous other single-institution studies 1,5,7–13 in both the surgical and radiology literature support the effectiveness of SCNB. False-negative rates of less than 4% have been reported, ^15–19 comparable to the 2.8% miss rate of NLB. Our results support SCNB as a reliable diagnostic alternative to excisional biopsy based on at least 2 years of follow-up in patients with a benign diagnosis at the initial SCNB.

The five false-negative results in this series identify several possibilities for failure to sample lesions accurately, including appropriate evaluation of pre- and postbiopsy images, recognition of discordance between the expected and actual histopathologic results, and the importance of the SCNB specimen radiograph. These results emphasize the need to adhere to the basic principles and guidelines when performing SCNB.

In patient 1 (see Table 3), there were several possible reasons for failure to obtain accurate histopathology, including needle malalignment on the pre- and postfire biopsy images, which could be a result of either patient movement or a possible “snowplow effect” of the lesion in the breast. The postbiopsy image appeared to reveal core-needle sampling defects typically seen in SCNB adjacent to, but not conclusively through, the lesion of concern. In addition, discordance between the initial histopathology (benign breast tissue) and the clinical impression (BI-RADS 4) was also apparent (i.e., no pathologic description was offered that explained the mammographic findings).

A similar histologic discordance occurred in patient 2: the initial SCNB was performed for calcifications, and the specimen was histologically negative for breast tissue. A specimen radiograph to confirm the presence of calcifications was not performed in this patient; this procedure is now routinely performed when SCNB is done for microcalcifications.

Patients 1 and 2 were considered true misses by SCNB because we could confidently determine the reason for sampling error.

Analysis of the additional three patients in whom DCIS was diagnosed was less clear. In contrast to the two patients in whom malignancy was diagnosed by repeat SCNB, in these three a definitive diagnosis was reached using NLB. To classify these lesions found to contain DCIS as true misses, we would need to prove that DCIS was present at the initial biopsy. Two of these patients had 6-month follow-up mammograms that were less suspicious, and routine follow-up was recommended. At 36-month follow-up (patient 3) and 12-month follow-up (patient 4), mammographic changes led to NLB, which showed DCIS. The suspicious areas that led to NLB were not clearly located in the same area as the initial lesion but were nearby. Patient 5 was lost to follow-up for 21 months and resurfaced with additional mammographic calcifications in the same general area as the initial SCNB, in which both the specimen radiograph and histopathology revealed microcalcifications. NLB in all three patients showed microscopic foci of DCIS. We must consider the possibility that DCIS in these three patients could have been an incidental finding in adjacent tissue at NLB, and the mammographic finding that led to the initial SCNB did not represent DCIS. Analysis of the number of cores taken at the initial SCNB showed that all five of these patients had more than six cores harvested. This should be an adequate tissue sampling and should not be a factor in false-negative results.

If all five of these patients are considered true misses at the time of the original SCNB, the false-negative rate is 4.3% in this series. If the latter three patients are excluded, then the false-negative rate drops to 1.7%. However, we can also assume that 2 additional false-negative lesions would be found in the 171 lesions lost to follow-up, which could raise the false-negative rate as high as 5.9%.

The need for adequate follow-up after benign biopsy is illustrated by our results. Seventy percent of the initial 571 lesions were available for at least 2 years of follow-up. This is comparable to the long-term (>24 months) follow-up rates reported in other series, which range from 55% to 85%. ^15,17 Incomplete follow-up at our institution is, in part, a function of a relatively heterogeneous patient population, which includes some noncompliant uninsured patients and patients who have shifted providers frequently as a result of annual changes in insurance coverage. In addition, many patients were lost to follow-up after being released to their primary care providers for routine mammographic screening. Before the end of this study period, a more detailed and specific protocol for follow-up of patients who undergo SCNB was instituted, and subsequent reports should be more complete and accurate.

The rate of rebiopsy in this series was 21.8% during the follow-up period. Others have reported a similar rebiopsy rate after the initial SCNB. ^18,22 Indications for rebiopsy included surgeon or patient concern, mammographic change, and an occasional mammogram interpreted by the radiologist as suspicious but by the surgeon as having the expected postbiopsy appearance. The threshold for rebiopsy during this period was further influenced by the relative inexperience of surgeons with the technique. In all five lesions that proved malignant on rebiopsy, the indication for reintervention was a suspicious result on follow-up mammography.

Although most lesions sampled in this series were BI-RADS 4 by screening mammography, a relatively high number (39%) were BI-RADS 3. This is comparable to the number of BI-RADS 3 lesions that underwent biopsy in a recent report evaluating the positive predictive value of the BI-RADS classification method. ²³ This may be a result of the retrospective mammographic review to stratify the radiologic risk classification into BI-RADS categories, but the malignancy rate for this entire series (16%) is consistent with that of other studies and of our reported series of NLB (17%), ²⁴ which was accumulated just before the initiation of SCNB by the same group of surgeons. Because of increased surgeon and patient concern about missing an early breast cancer during this initial experience with SCNB, more lesions that appeared benign on mammography (BI-RADS 2 or 3) underwent biopsy than is anticipated in the future. Although we know that the incidence of malignancy is low in BI-RADS 2 and 3 lesions, patient or surgeon anxiety will frequently lead to SCNB intervention in these patients, given the low complication rate of this procedure.

The role of image-guided breast biopsy and specifically SCNB in the evaluation and treatment of breast disease should be viewed in much the same way as laparoscopic surgery in the treatment of intraabdominal diseases. Both change the technique by which surgical treatment is delivered to multiple basic disease processes. Training and experience in breast anatomy, physiology, and pathophysiology are prominent features of surgical training and practice. Paradigms that exclude surgeons from the performance of all image-guided breast biopsies and especially SCNB in favor of radiologists have been suggested. ²⁵ However, this notion suggests that this procedure is purely one of breast imaging rather than another tool for use in the comprehensive care of patients with breast disease, malignant or benign. SCNB and image-guided procedures can be and have been included in a multispecialty approach to breast disease in many specialized centers. In our case, a collegial and cooperative relationship exists with radiologists in regard to the screening of patients who might benefit from SCNB. Surgeons perform the biopsies, and surgical consultation with a radiologist occurs at the time of the procedure when additional imaging interpretation and clarification are desired. However, the surgeon can independently manage this procedure in most instances. Because surgeons have extensive training in clinical decision making and the surgical management of patients with breast disease, they are well positioned to incorporate SCNB into the comprehensive care of these patients in clinical practice. Excluding surgeons from SCNB technology would be a mistake.

Continued diligence and follow-up after benign histopathology with SCNB are needed, and additional reports similar to this one are encouraged. Our results show an overall false-negative rate to date of 4.3%. This rate compares favorably with that from other reports. ^15–19 Our negative predictive value of 98.8% shows that patients and surgeons can feel confident that an accurate sample has been obtained when SCNB reveals benign histopathology. Our data represent the inclusive initial experience with SCNB of 12 surgeons and reflect the broad application of this technology to the evaluation and management of breast disease. Our results have identified important issues and problems in the management of nonpalpable breast lesions. Surgeon experience and training, including knowledge of breast pathophysiology and comprehensive treatment of both breast cancer and benign breast disease, are of paramount importance. The initial biopsies in four of the five patients with false-negative results were performed in the first 6 months of our experience with SCNB, supporting the notion that there is a physician learning curve. The previously discussed reasons for sampling error and delayed diagnosis reinforce the importance of adhering strictly to the basic principles of SCNB technique, histopathology interpretation, and follow-up protocols. We believe increased surgeon experience with SCNB will result in improved results in future reports.

Acknowledgments

The authors thank Donald E. Barker, MD, for editorial assistance, Michael D. Biderman, PhD, for database analysis, Patricia L. Lewis, RN, for manuscript assistance, and Jerome Abramson, MD, for assistance in histologic review.

Discussion

Dr. Benjamin F. Rush, Jr. (Newark, New Jersey): I find the results of this study comforting in three ways. First, only five of the 400 patients showed false-negatives (1.25%). Second, only one of these patients had evidence of invasive disease. And third, these fine results were obtained by a surgeon despite territorial claims for the method by others, usually radiologic services.

Since four of the five cases “missed” were found up to 12 or more months after the biopsies, it would be hard to prove whether these were missed lesions or new lesions. In fact, it is the normal practice to repeat mammographies every 12 months to determine if a new lesion has appeared despite negative films the year previously.

Core-needle biopsies can prove what you find but cannot necessarily predict what may occur later. Core-needle biopsy and similar techniques have been achieving increasing attention by the American College of Surgeons, by the surgeons of the Society of Surgical Oncology, and other surgical groups. Many of you with training programs should ask yourselves how much exposure your surgical residents are given to these methods and whether this may be an issue for the residency review committee in the future.

Finally, in view of the territorial nature of the procedure, I would like to ask Dr. Burns how he has arranged this program with his interventional radiologist.

Presenter Dr. R. Phillip Burns (Chattanooga, Tennessee): We arranged this program with our interventional radiologist by purchasing the equipment for the Department of Surgery and installing it in our faculty office. Our chief of radiology expressed some concern and a desire to start a competing program but then declined to do so when he saw our unit functioning well. I would further add that our unit was the first in our community. There are now three units and in all cases, the stereotactic biopsies are predominantly or exclusively performed by surgeons. This is a somewhat different experience than other areas of the country.

I appreciate your comments regarding resident education. Our surgical residents do receive training in this procedure, and for the past 3 years, graduating residents in our program have sufficient case volume to afford them full credentials in performance of stereotactic breast biopsy. I would encourage other programs to offer this opportunity to their surgical trainees.

Dr. Patricia J. Numann (Syracuse, New York): Dr. Burns, I agree with you that the clinical acumen of the surgeon is important in the decision to biopsy these lesions and the follow-up of these lesions. So I am enthusiastic about your results. My questions really relate to the best utilization of this procedure.

Forty-five percent of the lesions that you biopsied were BI-RADS 2 or 3, either benign or probably benign. Were these biopsies more for patient rather than physician concerns? Since this procedure is relatively atraumatic for most women, should biopsy be a choice to relieve patient anxiety rather than short integral mammograms to look at these borderline lesions?

Secondly, your series had a 16% yield of malignancy and four of the five lesions which were false-negative had the carcinoma late, were ductal carcinoma in situ, and the one that was invasive was in a 74-year-old woman. Should you be more stringent in your indications for biopsy?

Thirdly, you rebiopsied 21% of these women when only 1% of the total series of patients actually had a missed malignancy. Do you have recommendations to reduce this rebiopsy rate since this initial series?

Your follow-up algorithm also contains a recommendation for a 6-month interval film. Since 30% of your patients are lost to follow-up, how essential do you believe that 6-month film is, and do you have new criteria that would allow you not to recommend that for some of those women?

Lastly, your predictive value is excellent. Do you have recommendations for the rest of us on how to achieve these excellent results?

Dr. Burns: To answer the last question first, I believe that results with predictive value similar to ours will be forthcoming if surgeons become more involved in the performance of stereotactic breast biopsy. This is felt to be true in large part because of surgical training and understanding of the pathophysiology of breast disease and the follow-up clinical treatment of patients with breast disease, both benign and malignant.

In reference to your question regarding frequency of biopsy of BI-RADS 2 and 3 lesions, it is true that many of these biopsies were performed to allay the fears and paranoia of the patient, but frequently also to make the surgeon feel more secure. As you indicated, a firm tissue diagnosis goes a long way toward alleviating patient anxiety. It also makes the surgeon feel much more secure in recommendations for clinical and mammographic follow-up. We do have to guard against the criticism that we run true to the adage that “if you have a hammer, the whole world looks like a nail.” The ready availability and close proximity of the unit within our faculty office complex does make this procedure readily available to us and patients. At this point, usage rates are stable.

Our overall 16% malignancy is lower than some reported series. We have become somewhat more selective in biopsy of less suspicious lesions but again, frequently yield to the anxiety and fears of our patients. Many of them know this procedure is available either in our office or in other areas of the country and do not feel adequately treated unless a tissue diagnosis has been rendered.

The rebiopsy rate of 21% was somewhat higher than we had anticipated. As indicated in the presentation, this was the inclusive experience of our faculty from the start of this service, and there was a very low threshold to proceed to rebiopsy early in the series. While I do not have accurate current data of the rebiopsy rate, it is substantially lower. We do maintain a low threshold for rebiopsy, especially in patients who have calcification in the lesion area as an indication for initial biopsy.

Your question regarding mammographic follow-up at 6-month intervals is perceptive. We have begun to lengthen this time frame and now frequently obtain our follow-up at yearly intervals instead of 6 months postbiopsy. This interval is obviously affected by the type of lesion that provoked the initial biopsy.

Dr. C. Barber Mueller (Hamilton, Ontario, Canada): It was Thiersch who more than 100 years ago made sequential biopsies of cutaneous lesions and documented the histopathologic changes from normal cells to malignant cells in squamous cell carcinoma. Even now this has not been done on the breast. The sequence of events in ductal epithelium has been inferential from single observations on many women rather than multiple observations on a single woman. Your greatest contribution may be to do sequential sampling over time and, like Thiersch, document the changes between normal and cancerous epithelium and relate these pathologic abnormalities to mammographic abnormalities.

I guess my only question is to ask if you might be encouraged to do a study of sequential biopsies. This would be clinical research à la Pruitt. It would be a major contribution to pathologists, to mammographers, and to women.

Dr. Burns: We do not have a formalized program or research study currently in effect to sequentially study the evolution of benign disease. We have looked at our rate of concordance in patient groups who undergo rebiopsy and have found it interesting that a substantial number of them change from proliferative to nonproliferative and vice versa. This certainly is an idea that would be ripe for additional study in the future, and I appreciate your suggestion that we might consider such.