How Many Lymphedema Cases are there in the U.S?

MORE THAN 6.8 MILLION INDIVIDUALS

In the U.S., within the Medicare age population, the number of persons afflicted with lymphedema, or at risk of developing it, exceeds 6.8 million individuals. This is a lot of affected individuals for a condition is is so often neglected or ignored by the medical community.

In 2007 when this question was put to Robert Weiss, M.S., who is well known as “the LymphedemaAdvocate,” he initiated a literature review on this topic, the following is his response and the data he made available to be shared with Lymph Notes members and visitors.

BACKGROUND

When he started on this project, Mr Weiss observed that there was a TOTAL lack of information on the prevalence of lymphedema. As he said, "I was forced to make what I hope is a credible estimate using the literature. I am behind in reviewing the literature of the last couple of years, but I believe that the following data is still valid.

Accurate estimates of the incidence of lymphedema were difficult to find because.

• The lack of a standard clinical definition of the condition.
• Very few consistent surveys have appeared in the literature.
• The occurrence of lymphedema is so dependent on the patient's genetic predisposition to develop this condition,
• The patient's general health and lymphatic system health, including the  nature and extent of lymphatic trauma.

RESEARCH METHODS USED

An extensive literature search was performed on over 1,900 references to primary and secondary lymphedema. Over 200 references which cited the incidence of lymphedema from any cause were abstracted and the relevant statistics collected into a matrix citing these references:

• The causes of the lymphedema.
• Appropriate statistics.
• The number of cases.
• The years of treatment.
• The length of the study.
• How the lymphedema measurements are obtained and used.

THE RESULTS

The incidence of lymphedema compared, and contrasted, with an attempt to derive consistent estimates for individual procedures or causes. The majority of the estimates relate to breast cancer treatment protocols, but the survey includes pelvic and inguinal treatment protocols as well as estimates of primary lymphedema incidence.

Dispersion between references is demonstrated to be caused by changing diagnosis and treatment during studies, lack of standard measurement and grading criteria, prolonged course of toxicity, therapeutic interventions during the study, physicians' viewpoints and knowledge, inadequate contemporary documentation, selection criteria of patients for study and non-use of actuarial estimates.

The Onset of lymphedema is shown to vary as a function of the method of measurement and the causative therapeutic procedure. Toxic effects of radiotherapy do not become fully evident until many years after treatment. Using sensitive lymphoscintigraphic measures of lymphedema, Campisi 2003 shows early effects of breast cancer treatment at 3-6 months (range <1 to 24 months).

The delayed effects of radiotherapy are demonstrated [ref: Pierquin 1986] with median onset at 7 (range 2-37) months with surgery alone, 12 (1-52) months with surgery and radiation and 25 (6-156) months with radiation alone. Other researchers demonstrate medians between 1 and 2 years, with maximum times of onset of 3 to 10 years for mixed cohorts.

Swelling after breast cancer treatment can occur at a number of sites, and the restriction of measurements to one particular site such as the forearm, upper arm or entire arm and hand results in an underestimation of the incidence of lymphedema. Arm swelling may account for only about half of the patient-reported swelling [ref:Bosompra et al 2002].

Other reported sites include the breast, chest, underarm and back. But measurement of these sites is very difficult and so have remained largely unreported. Breast lymphedema incidences of 70% using measurement of dermal swelling have been demonstrated [ref: Rönkä 2004] while clinical examination detects only 35% in the same cohort.

Changes in the mix of breast cancer surgery and radiotherapy over the last 50 years have resulted in a change in the incidence of lymphedema, since each therapy has a different associated morbidity. Halsted Radical Mastectomies with and without radiotherapy, the standard until the 1970's, resulted in upper limb lymphedema rates of 22-44% without and with radiotherapy. With the ascendancy of the less radical Modified Radical Mastectomy in the 1970's and 1980's lymphedema rates fell to 19-29% without, and with, radiotherapy [ref: Schünemann & Willich 1997].

The 1990's brought Breast Conserving Surgery from a small percentage to approximately half of the surgeries performed [ref:Yoshimoto et al 2004] with a further drop in upper limb lymphedema rates to 7-10% without and with radiotherapy [ref:Schünemann & Willich 1997].

Breast lymphedema started to receive attention in 1982, with Kissin reporting clinical rates of 8% and Clarke reporting rates of 41% using skin measurements. Recent reports estimate the rates 1-9% based on subjective reporting [ref:Fehlauer 2003] [ref:Højris 2000], 10-19% based on clinical examination [ref:Fehlauer 2003] [ref:Goffman 2004] 20-48% [ref:Rönkä 2004] [ref:Senofsky 1991] and 30-70% based on skin thickness measurement [ref:Rönkä 2004].

Lower limb lymphedema rates are likewise a strong function of the extent of the surgery and radiation used for treatment of reproductive and pelvic cancers, as well as lower limb melanomas. Whereas there are many different methods commonly used to evaluate upper limb swelling, there are very few methods reported to measure lower limb swelling.

Lower limb lymphedema is reported in medical records only when it is severe enough that compression is not adequate, or causes disablement. Reported lower limb lymphedema ranges from zero [ref:Coblenz 2002] to 60-80% [ref:Balzer 1993] [ref:James 1982] [ref:Papachristou 1977] with many reports between these extremes.

Lymphedema of the genitals has been reported as 2-5% [ref:Gaarenstroom 2003] [ref:Nelson 2004] and 18% (combined with lower limb) [ref:Lieskovsky 1980]. Genital lymphedema among users of pneumatic pumps on the lower limb has been reported at 43% [ref:Boris 1998].

Prevalence of primary lymphedema has been estimated as 1.15/100,000 persons under 20 years [ref:Smeltzer 1985].

CONCLUSIONS

Bob Weiss, LymphActivist

This systematic review of lymphedema references results in an estimate of lymphedema incidence overall and by causative factor. We can use these incidence statistics to estimate prevalence.

• INCIDENCE: The incidence of lymphedema as a consequence of breast cancer treatment (surgery and/or radiation) ranges from 10 to 40%.
• PREVALENCE: The prevalence of invasive cancer survivors in the U.S in 2002 has been estimated by the National Cancer Institute as 9.6 Million, of whom 61% (5.86 Million) are over 65 years of age.
• Add to this number an estimate of how many persons underwent surgeries known to lead to lymphedema. For example, coronary artery by-pass grafts (277,000 over 65 in 2002), hip and knee replacements (314,000 over 65 in 2002), and cellulitis (374,000 over 65 in 2002), and the population of afflicted and at risk persons of Medicare age exceeds 6.8 million in the U.S.
• A 20% incidence of lymphedema yields a potential of 1.36 million cases of Lymphedema of the upper limbs, lower limbs, head and neck, breast and torso in this Medicare population. Note that this estimate does not include probably an equal number of patients suffering from lymphedema secondary to chronic venous insufficiency.

ACKNOWLEDGEMENT AND GRATITUDE

Our thanks to Robert Weiss, M.S. The LymphedemaAdvocate, who compiled this information and can be contacted by e-mail at LymphActivist@aol.com.

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Category: Are You at Risk for Lymphedema? Updated: 2013-03-23