- Email: [email protected]
The elimination of leukemic cells from autologous marrow by hyperthermia
Int. J. Radiorion Oncology Biol. Phys.. Vol. Printed in the U S.A. Allrights reserved.
036C~3016/82/11203343$03.00/0 Copyright 0 1982 Pergamon Press Ltd.
8, pp. 2033-2035
??Correspondence Letters to the Editor will be published if they are suitable and if space permits. The Letter sboqld be typewritten (double spaced) and must not exceed 1% pages including references; submit in triplicate. The Letter may be edited and sbortqned in our Editorial Office. A letter regarding a recent Journal article should be received within six weeks of the article’s publication date.
the Japanese Joint Committee, whose task forces are modelled on the American patttern and whose documentation and statistics are immaculate in their conception (if you will forgive the analogy); the Deutschsprachiger TNM-Auschuss, the German-speaking committee of West Germany, Switzerland and Austria; the Canadian Joint Committee; several international organizations such as the ICPR, FIGO, SIOP and so on. All these wish to have their say and rightly so. The AJCC is shortly to publish a revised edition of the Manual For Staging of Cancer and Dr. Oliver Beahrs, its Executive Director, has done me the honor of inviting my criticisms of the draft. In doing so I will point out that the UICC intend to revise their Livre de Poche in 1986-a year chosen to coincide with the tenth revision of the International Classification of Diseases for Oncology (ICD-0: WHO). At the present time the 3rd edition of the Livre de Poche has been translated into I1 languages and the 28 site-classifications have been adopted world-wide. Yet there remains this depressing thought: of these 28, only one is identical in content with the same number in the AJCC Manual. Some, it is true, are almost the same, but many are so different that meaningful comparison between the two is impossible. Herein lies the opportunity for consensusdr chaos! Permit me to illustrate this with a personal letter which I received from an English colleague recently returned from a lecture tour in America: Relative to this, may I tell you how disappointed I was on my recent trip to find that the UICC system is not widely used. The whole of the States seems to be dominated by the American College of Surgeons’ [sic] classification, which in fact introduces quite a lot of difficulty in communication. I thought your committee had succeeded in getting the Americans to adopt the UICC system, but they sem to be backsliding.. Well, of course Americans are not ‘backsliding.’ My correspondent is but one of many who does not fully understand what has gone before and what many of us, on both sides of the Atlantic, have been trying to achieve over the years. Nevertheless, this quotation epitomizes the impatience with which many oncologists view the incompetence of those who should by now have found a solution to this problem. It is this ‘solution’ which I am now bold enough to suggest. That an International Commission should be assembled (under whose auspices is yet to be determined) and at which the TNM system of classification for all anatomical sites of malignant tumors should be agreed for publication in 1986. Then, and only then, will we be able to equate with Saint Thomas Aquinas and claim with him: They are called wise who put things in their right order.
TNM MARCHES ON To the Editor: Many years ago I used to go to the Cinema [syn: the Movies] and enjoy a weekly news-program which invariably ended with the stirring words ‘Time Marches On!’ It is the recollection which prompts me to plagiarize those words as the heading of this letter to your Journal. I write to put the case for international agreement on a system of classification for malignant tumors which I believe is now generally accepted throughout the world as being the best that has so far been devised. It is proper that I should remind readers that the TNM system was first proposed by Denoix’ in France, that it was accepted by the International Union Against Cancer (UICC) and that in the last 25 years or so many countries have adopted it as a basis for comparing the results of treatment-which, in the last analysis, is what really matters. Not least among these was the American Joint Committee for Cancer Staging and End Results Reporting (AJC; now the American Joint Committee on Cancer, or AJCC). As with so many things which are undertaken in America-the AJC made a splendid success of disseminating the TNM system, but it did so according to its own convictions (which is to say the considered opinions of the experts serving on its several ‘task forces’) but without, unhappily, the full cooperation of those other experts on the UICC TNM committee. It is not my intention to provoke dissent: to the contrary. Yet it may be helpful to recall some of the incidents in the comparatively short history of this endeavor and to intersperse these with a few aphorisms and obiter dicta. For the dedicated oncotaxonomist, A.H. Sellers’s “Development of the TNM System”’ will provide the full story. To those more impatient in their search for truth, a few of my own ‘Thoughts” may appeal. For example: Everyone agrees in general: no one agrees in pariicular. Der Teufel laueri in den Einzelheiten. (An apt German proverb: The Devil lurks in the details). Any international classification is better than half a dozen national remarked when classifications. (But per contra, as Dr. Haagensen debating the relative merits of the Columbia breast staging and the UICC Classification with me on one occasion: “because a thing is international it does not follow that it is necessarily best”). Classification preceeds staging. Or to put it another way, classification must be universal and immutable, while staging may be personal and changeable. And this is acceptable since staging is but a compilation of the several T, N and M categories. Again, it may amuse your readers to be reminded of an incident which occurred in 1968 when I was invited to attend a meeting, on behalfof the UICC, by the AJC at the College of Surgeons in Chicago. It was my brief to plead the case for international cooperation and my lack of success was summarized in an [unpublished] memorandum, “Failure of a Mission.” I quote: At the end of a somewhat abrasive debate in which Mr. Harmer reproached the AJC for lack of cooperation, Dr. Murray Copeland, summing-up from the Chair and anxious to pour oil upon the troubled waters, observed that at least the AJC and the UICC “would continue to cooperate along parallel lines.” To which Mr. Harmer replied that, by definition, parallel lines met at infinity! What follows? The fact is that not only the UICC and the AJCC need to come together. There are other TNM Committees in the field as well:
MICHAEL HARMER, MB FRCS Consultant Editor, UICC Committee on TNM Classification Perrot Wood, GrafTham, Petworth Sussex GU28 ONZ England
1. Denoix, P.F.: Bull. Nat. Insr. Hygiene I: 69, 1944. 2. Harmer, M.H.: The case for TNM. Clin. Oncol. 3: 131, 1977. 3. Sellers, A.H.: The Classification of Malignant Tumours: Development of the TNM System. UICC, Geneva. 1980.
THE ELIMINATION OF LEUKEMIC CELLS FROM AUTOLOGOUS MARROW BY HYPERTHERMIA To the Editor: We were most interested to read the paper by Rubin et a/ entitled “The separation of a mixture of bone marrow stem cells.” The subtitle “An essential step for autologous marrow transplantation” neatly summarizes the problem. Unless malignant cells can be removed from autologous marrow, this technique is unlikely to be clinically
2033
2034
Radiation Oncology
0 Biology 0 Physics
useful. The results presented by Rubin et al.’ suggest that centrifugal elutriation is a very promising technique. We have investigated the same problem and have used hyperthermia to selectively eliminate leukemic cells from autologous marrow. Normal or leukemic femoral bone marrow from DBA, mice was heated in vitro and assayed in viva by the spleen colony assay technique. The experiments are described in detail elsewhere.’ Briefly we have observed a striking difference in the heat sensitivities of normal hemopoietic stem cells and Ll2lO leukemia clonogenic cells in mouse bone marrow, the leukemic cells being much more sensitive. These results are depicted in Fig I, which shows survival curves for normal and leukemic CFU-S for various heating times at 43°C. Fitting the data to a multi-target survival equation of the form S=l-(l-e m”‘m)n yielded the parameter indicated in Fig. I. These results are for DBA, mice. However, it is interesting to speculate on the clinical implications, should a similar differential heat sensitivity exist for some forms of human leukemia. In human marrow transplantation it is common for IO9 marrow cells/kg to be aspirated, while it appears that lo’-IO8 cells/kg are usual sufficient for successful engrafting.‘. Hence, a one-decade reduction in the number of hemopoietic stem cells in aspirated marrow should nevertheless permit engraftment. With the differential survival curves shown in Fig I. a one-decade reduction in normal stem cell number corresponds to a more than five-decade reduction in the leukemic cell number (extrapolating the curve for leukemic cells in Fig I), implying the possible elimination of more than IO’ leukemic cells by hyperthermia. However, caution is required in the interpretation of these results, as well as in the extrapolation from mouse to man. In addition to these findings, we have also observed the important influence of complicating factors such as the age and composition of the medium in which the cells are heated and the possible importance of cell-cell interactions in hyperthermia responses. Specifically, we have observed that there is no significant difference in heat sensitivity between Ll210 cells obtained
Surviving fraction
November 1982, Volume 8, Number I I
from ascites tumors and normal marrow stem cells. However, when Ll210 ascites cells are mixed with normal bone marrow cells during heating, their sensitivity is markedly increased. It is possible that the increased heat sensitivity of Ll2 IO cells taken from bone marrow, and of Ll2lO ascites cells heated in the presence of normal marrow cells results from a cell-to-cell interaction effect. One possible cause of such an effect could be the release of cytotoxic lysosomal enzymes by heat-damaged marrow cells.’ Nevertheless, the results described provide grounds for cautious optimism that extracorporeal hyperthermia may prove useful in the selective elimination of leukemic cells (and perhaps other neoplastic cells) from autologous bone marrow. Of course, for differential cell killing by hyperthermia, the malignant cells must be more sensitive to heat. Cell separation by centrifugal elutriation relies upon differences in cell volume. Either method may yield better results in some circumstances. Since these methods are not mutually exclusive, it may sometimes be possible to further reduce the number of malignant cells in marrow by combining both modalities, R.P. SYMONDS, M.D., MRCP, FRCR Glasgow Institute of Radiotherapeutics Western Infirmary Glasgow T.E. WHELDON, PH.D. MRC Cyclotron Unit Hammersmith Hospital London WI2
Goldman J.M.: Hemopoetic stem cell autographs for leukemia. Blur 41: 71-79. 1980. Int. J. Radiat. Uncol. Biol. Rubin, P.: Bone marrow autografting. fhys. 2: 213-214. 1977. Rubin, P.. Wheeler, K.T., Keng, P.C.. Gregory, P.K.. Croizat, H.: The separation of a mixture of bone marrow cells: An essential step for autologous bone marrow transplantation. Inr. J. Radiut. Oncol. Biol. Phys. 7: 1405-1411, 1981. Symonds, R.P.. Wheldon, T. E., Clarke, B., Bailey, G.: A comparison of the response to hyperthermia of murine hemopoietic stem cells (CFU-S) and Ll210 leukemic cells in the presence of normal marrow cells. Br. J. Cancer 44: 682-691, 1981.
Critique
D.B. Hughes 7~1725-1726,
_
&
Leu kaemic n=137 Do=l.lOmin.
Time Fig. I. cells in various Survival
(
minutes)
Survival of normal (CFU-S) and Ll210 leukemia stem DBA, mouse bone marrow after heating in vitro for times at 43°C in a precision-controlled water-bath. was assessed in vivo by spleen colony assay.
and Oncology
of TRANSPARENT
BLOCKS-AN SIMULATION
and R. Rodriguez, 1981
IN.
J. Radiat.
AID IN
Oncol.
Biol.
Phys.
To the Editor: The contribution of Hughes and Rodriguez’ is a welcome edition to the technology of radiation therapy. We suggest a word ofcaution. Using the “thin transparent block” (TTB) method with between the a rapered blocking system, there will be a concordance simulation films and the beam (port) films whether one places the TTB to simulate either upper or lower surfaces of the customary 4-half value layer (4HVL) thick therapy blocks (Fig. I). In those radiation therapy departments using a non-tapered blocking system, a visual disparity occurs between the simulation and beam films depending on whether the TTB is used to depict the upper or lower margin of the 4HVL blocks. For example, in simulating the lung block around a hilar mass, if the shadow tray of the simulator is set so the TTB depicts the lower margin of the block, then a zone exists within the lung seemingly blocked on the simulation film where only the geometric penumbra dose (varying between 50% of the central axis dose at the edge of the light field to 5% as the diverging beam traverses the 4HVL thickness of the block) is delivered. In effect, there will be a somewhat wider margin around the hilar mass than is visually apparent on the simulator film-but also more normal tissue is receiving some radiation dosage (left side of Fig. 2). On the othe hand, if the simulator shadow tray is set so that the TTB depicts the upper edge of the 4HVL lung block, on viewing the simulator film, the therapist must realize that a zone ofseemingly unblocked lung, for example, medially toward the hilum, will only be getting the geometric penumbra dose. In effect, the “full-dose” margin around the
036C~3016/82/11203343$03.00/0 Copyright 0 1982 Pergamon Press Ltd.
8, pp. 2033-2035
??Correspondence Letters to the Editor will be published if they are suitable and if space permits. The Letter sboqld be typewritten (double spaced) and must not exceed 1% pages including references; submit in triplicate. The Letter may be edited and sbortqned in our Editorial Office. A letter regarding a recent Journal article should be received within six weeks of the article’s publication date.
the Japanese Joint Committee, whose task forces are modelled on the American patttern and whose documentation and statistics are immaculate in their conception (if you will forgive the analogy); the Deutschsprachiger TNM-Auschuss, the German-speaking committee of West Germany, Switzerland and Austria; the Canadian Joint Committee; several international organizations such as the ICPR, FIGO, SIOP and so on. All these wish to have their say and rightly so. The AJCC is shortly to publish a revised edition of the Manual For Staging of Cancer and Dr. Oliver Beahrs, its Executive Director, has done me the honor of inviting my criticisms of the draft. In doing so I will point out that the UICC intend to revise their Livre de Poche in 1986-a year chosen to coincide with the tenth revision of the International Classification of Diseases for Oncology (ICD-0: WHO). At the present time the 3rd edition of the Livre de Poche has been translated into I1 languages and the 28 site-classifications have been adopted world-wide. Yet there remains this depressing thought: of these 28, only one is identical in content with the same number in the AJCC Manual. Some, it is true, are almost the same, but many are so different that meaningful comparison between the two is impossible. Herein lies the opportunity for consensusdr chaos! Permit me to illustrate this with a personal letter which I received from an English colleague recently returned from a lecture tour in America: Relative to this, may I tell you how disappointed I was on my recent trip to find that the UICC system is not widely used. The whole of the States seems to be dominated by the American College of Surgeons’ [sic] classification, which in fact introduces quite a lot of difficulty in communication. I thought your committee had succeeded in getting the Americans to adopt the UICC system, but they sem to be backsliding.. Well, of course Americans are not ‘backsliding.’ My correspondent is but one of many who does not fully understand what has gone before and what many of us, on both sides of the Atlantic, have been trying to achieve over the years. Nevertheless, this quotation epitomizes the impatience with which many oncologists view the incompetence of those who should by now have found a solution to this problem. It is this ‘solution’ which I am now bold enough to suggest. That an International Commission should be assembled (under whose auspices is yet to be determined) and at which the TNM system of classification for all anatomical sites of malignant tumors should be agreed for publication in 1986. Then, and only then, will we be able to equate with Saint Thomas Aquinas and claim with him: They are called wise who put things in their right order.
TNM MARCHES ON To the Editor: Many years ago I used to go to the Cinema [syn: the Movies] and enjoy a weekly news-program which invariably ended with the stirring words ‘Time Marches On!’ It is the recollection which prompts me to plagiarize those words as the heading of this letter to your Journal. I write to put the case for international agreement on a system of classification for malignant tumors which I believe is now generally accepted throughout the world as being the best that has so far been devised. It is proper that I should remind readers that the TNM system was first proposed by Denoix’ in France, that it was accepted by the International Union Against Cancer (UICC) and that in the last 25 years or so many countries have adopted it as a basis for comparing the results of treatment-which, in the last analysis, is what really matters. Not least among these was the American Joint Committee for Cancer Staging and End Results Reporting (AJC; now the American Joint Committee on Cancer, or AJCC). As with so many things which are undertaken in America-the AJC made a splendid success of disseminating the TNM system, but it did so according to its own convictions (which is to say the considered opinions of the experts serving on its several ‘task forces’) but without, unhappily, the full cooperation of those other experts on the UICC TNM committee. It is not my intention to provoke dissent: to the contrary. Yet it may be helpful to recall some of the incidents in the comparatively short history of this endeavor and to intersperse these with a few aphorisms and obiter dicta. For the dedicated oncotaxonomist, A.H. Sellers’s “Development of the TNM System”’ will provide the full story. To those more impatient in their search for truth, a few of my own ‘Thoughts” may appeal. For example: Everyone agrees in general: no one agrees in pariicular. Der Teufel laueri in den Einzelheiten. (An apt German proverb: The Devil lurks in the details). Any international classification is better than half a dozen national remarked when classifications. (But per contra, as Dr. Haagensen debating the relative merits of the Columbia breast staging and the UICC Classification with me on one occasion: “because a thing is international it does not follow that it is necessarily best”). Classification preceeds staging. Or to put it another way, classification must be universal and immutable, while staging may be personal and changeable. And this is acceptable since staging is but a compilation of the several T, N and M categories. Again, it may amuse your readers to be reminded of an incident which occurred in 1968 when I was invited to attend a meeting, on behalfof the UICC, by the AJC at the College of Surgeons in Chicago. It was my brief to plead the case for international cooperation and my lack of success was summarized in an [unpublished] memorandum, “Failure of a Mission.” I quote: At the end of a somewhat abrasive debate in which Mr. Harmer reproached the AJC for lack of cooperation, Dr. Murray Copeland, summing-up from the Chair and anxious to pour oil upon the troubled waters, observed that at least the AJC and the UICC “would continue to cooperate along parallel lines.” To which Mr. Harmer replied that, by definition, parallel lines met at infinity! What follows? The fact is that not only the UICC and the AJCC need to come together. There are other TNM Committees in the field as well:
MICHAEL HARMER, MB FRCS Consultant Editor, UICC Committee on TNM Classification Perrot Wood, GrafTham, Petworth Sussex GU28 ONZ England
1. Denoix, P.F.: Bull. Nat. Insr. Hygiene I: 69, 1944. 2. Harmer, M.H.: The case for TNM. Clin. Oncol. 3: 131, 1977. 3. Sellers, A.H.: The Classification of Malignant Tumours: Development of the TNM System. UICC, Geneva. 1980.
THE ELIMINATION OF LEUKEMIC CELLS FROM AUTOLOGOUS MARROW BY HYPERTHERMIA To the Editor: We were most interested to read the paper by Rubin et a/ entitled “The separation of a mixture of bone marrow stem cells.” The subtitle “An essential step for autologous marrow transplantation” neatly summarizes the problem. Unless malignant cells can be removed from autologous marrow, this technique is unlikely to be clinically
2033
2034
Radiation Oncology
0 Biology 0 Physics
useful. The results presented by Rubin et al.’ suggest that centrifugal elutriation is a very promising technique. We have investigated the same problem and have used hyperthermia to selectively eliminate leukemic cells from autologous marrow. Normal or leukemic femoral bone marrow from DBA, mice was heated in vitro and assayed in viva by the spleen colony assay technique. The experiments are described in detail elsewhere.’ Briefly we have observed a striking difference in the heat sensitivities of normal hemopoietic stem cells and Ll2lO leukemia clonogenic cells in mouse bone marrow, the leukemic cells being much more sensitive. These results are depicted in Fig I, which shows survival curves for normal and leukemic CFU-S for various heating times at 43°C. Fitting the data to a multi-target survival equation of the form S=l-(l-e m”‘m)n yielded the parameter indicated in Fig. I. These results are for DBA, mice. However, it is interesting to speculate on the clinical implications, should a similar differential heat sensitivity exist for some forms of human leukemia. In human marrow transplantation it is common for IO9 marrow cells/kg to be aspirated, while it appears that lo’-IO8 cells/kg are usual sufficient for successful engrafting.‘. Hence, a one-decade reduction in the number of hemopoietic stem cells in aspirated marrow should nevertheless permit engraftment. With the differential survival curves shown in Fig I. a one-decade reduction in normal stem cell number corresponds to a more than five-decade reduction in the leukemic cell number (extrapolating the curve for leukemic cells in Fig I), implying the possible elimination of more than IO’ leukemic cells by hyperthermia. However, caution is required in the interpretation of these results, as well as in the extrapolation from mouse to man. In addition to these findings, we have also observed the important influence of complicating factors such as the age and composition of the medium in which the cells are heated and the possible importance of cell-cell interactions in hyperthermia responses. Specifically, we have observed that there is no significant difference in heat sensitivity between Ll210 cells obtained
Surviving fraction
November 1982, Volume 8, Number I I
from ascites tumors and normal marrow stem cells. However, when Ll210 ascites cells are mixed with normal bone marrow cells during heating, their sensitivity is markedly increased. It is possible that the increased heat sensitivity of Ll2 IO cells taken from bone marrow, and of Ll2lO ascites cells heated in the presence of normal marrow cells results from a cell-to-cell interaction effect. One possible cause of such an effect could be the release of cytotoxic lysosomal enzymes by heat-damaged marrow cells.’ Nevertheless, the results described provide grounds for cautious optimism that extracorporeal hyperthermia may prove useful in the selective elimination of leukemic cells (and perhaps other neoplastic cells) from autologous bone marrow. Of course, for differential cell killing by hyperthermia, the malignant cells must be more sensitive to heat. Cell separation by centrifugal elutriation relies upon differences in cell volume. Either method may yield better results in some circumstances. Since these methods are not mutually exclusive, it may sometimes be possible to further reduce the number of malignant cells in marrow by combining both modalities, R.P. SYMONDS, M.D., MRCP, FRCR Glasgow Institute of Radiotherapeutics Western Infirmary Glasgow T.E. WHELDON, PH.D. MRC Cyclotron Unit Hammersmith Hospital London WI2
Goldman J.M.: Hemopoetic stem cell autographs for leukemia. Blur 41: 71-79. 1980. Int. J. Radiat. Uncol. Biol. Rubin, P.: Bone marrow autografting. fhys. 2: 213-214. 1977. Rubin, P.. Wheeler, K.T., Keng, P.C.. Gregory, P.K.. Croizat, H.: The separation of a mixture of bone marrow cells: An essential step for autologous bone marrow transplantation. Inr. J. Radiut. Oncol. Biol. Phys. 7: 1405-1411, 1981. Symonds, R.P.. Wheldon, T. E., Clarke, B., Bailey, G.: A comparison of the response to hyperthermia of murine hemopoietic stem cells (CFU-S) and Ll210 leukemic cells in the presence of normal marrow cells. Br. J. Cancer 44: 682-691, 1981.
Critique
D.B. Hughes 7~1725-1726,
_
&
Leu kaemic n=137 Do=l.lOmin.
Time Fig. I. cells in various Survival
(
minutes)
Survival of normal (CFU-S) and Ll210 leukemia stem DBA, mouse bone marrow after heating in vitro for times at 43°C in a precision-controlled water-bath. was assessed in vivo by spleen colony assay.
and Oncology
of TRANSPARENT
BLOCKS-AN SIMULATION
and R. Rodriguez, 1981
IN.
J. Radiat.
AID IN
Oncol.
Biol.
Phys.
To the Editor: The contribution of Hughes and Rodriguez’ is a welcome edition to the technology of radiation therapy. We suggest a word ofcaution. Using the “thin transparent block” (TTB) method with between the a rapered blocking system, there will be a concordance simulation films and the beam (port) films whether one places the TTB to simulate either upper or lower surfaces of the customary 4-half value layer (4HVL) thick therapy blocks (Fig. I). In those radiation therapy departments using a non-tapered blocking system, a visual disparity occurs between the simulation and beam films depending on whether the TTB is used to depict the upper or lower margin of the 4HVL blocks. For example, in simulating the lung block around a hilar mass, if the shadow tray of the simulator is set so the TTB depicts the lower margin of the block, then a zone exists within the lung seemingly blocked on the simulation film where only the geometric penumbra dose (varying between 50% of the central axis dose at the edge of the light field to 5% as the diverging beam traverses the 4HVL thickness of the block) is delivered. In effect, there will be a somewhat wider margin around the hilar mass than is visually apparent on the simulator film-but also more normal tissue is receiving some radiation dosage (left side of Fig. 2). On the othe hand, if the simulator shadow tray is set so that the TTB depicts the upper edge of the 4HVL lung block, on viewing the simulator film, the therapist must realize that a zone ofseemingly unblocked lung, for example, medially toward the hilum, will only be getting the geometric penumbra dose. In effect, the “full-dose” margin around the